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Sample records for s-type cape granite

  1. The role and fate of peritectic garnet in S-type granite Petrogenesis: The example of the Cape Granite Suite (South Africa)

    Science.gov (United States)

    Villaros, A.; Stevens, G.; Buick, I.

    2007-12-01

    The 560-530 Ma S-type components of the Cape Granite Suite (CGS) vary in composition from granodiorite to leucogranite. In places these rocks contain an abundance of xenoliths, including rare granulite facies metasediments and metabasic rocks. Thermobarometry applied to these assemblages gives consistent results of 850 ± 45 °C and 9 ± 1 kbar. These conditions are interpreted to reflect those of the source area at the time of magma genesis and lie within the experimentally determined interval for biotite fluid-absent melting, which, under these conditions, produces garnet as the dominant peritectic phase. Entrainment of different proportions of this generation of garnet (up to 20wt%) into the experimentally determined leucocratic melt compositions produces magma compositions that match well with the major element bulk composition of the CGS S-type granites. Zr and Fe + Mg are strongly positively correlated in the CGS S-types, and in many rocks occur in concentrations exceeding those possible in pure melts. This indicates the co-entrainment of peritectic garnet, derived from biotite breakdown, and, and zircon, typically hosted as an inclusion within biotite prior to anatexis. A model for the trace element composition of the granites, that is a near perfect fit with the natural rocks, can be created by applying a partial disequilibrium melting model. In this model, elements contained within pre- existing metamorphic garnet and the refractory fraction of zircon are not available for sequestration into the melt and melt trace element abundance is a function of the trace element composition of the accessible portion of the source, the fraction of zircon that dissolves and partitioning between melt and the peritectic garnet and other residual minerals. Magma trace element compositions are a function of the melt composition and the compositions of the entrained garnet, zircon and other accessory minerals such as monazite. Ce concentration in the granites over that which

  2. Chemical characteristics of zircon from A-type granites and comparison to zircon of S-type granites

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    Breiter, Karel; Lamarão, Claudio Nery; Borges, Régis Munhoz Krás; Dall'Agnol, Roberto

    2014-04-01

    fractionated Cínovec cupola (Erzgebirge), the Zr/Hf value decreases from 33-51 in the protolithionite granite at a depth of 1255 m to 7.5-25 in the zinnwaldite granite at a depth of 40 m. At the scale of individual crystals, the Zr/Hf value decreases from 86 to 68 from the cores to the rims of the zircons from the Teplice rhyolite and from 64 to 33 in the zircons from the biotite granite at Krupka, Erzgebirge. The contents of Hf and U in zircon are dependent mainly on the degree of granite fractionation and the nature and volume of the volatile phases and are independent of the A- or S-character of the parental melt. The zircon Zr/Hf ratios 55 and 25 are proposed to approximately distinguish common, moderately evolved and highly evolved granites. Zircons from the moderately and highly evolved granites of A- and S-type can be discriminated on the basis of their HREE content and the U/Th ratios. Nb, Ta, and W are present in zircon from the highly evolved granites from all studied areas, while high As, Bi, and Sc contents are typical only for the Erzgebirge.

  3. Origin of enclaves in S-type granites of the Lachlan Fold Belt

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    Chappell, Bruce W.; Wyborn, Doone

    2012-12-01

    The more mafic S-type granites of the Lachlan Fold Belt contain a distinctive assemblage of lithic inclusions of deep crustal origin. Two types predominate, the schistose enclaves and the microgranular enclaves. There is also a small proportion of fragments of local country rock. All the features of the schistose enclaves are consistent with an origin as lithic restite fragments from the source. Their ubiquity in the mafic S-type granites and absence from both felsic S-type granites and I-type granites, conform with such an origin. The argument that these enclaves are not in chemical equilibrium with the host granite because they do not complement its composition is not valid, since they represent less fertile parts of the source that had different compositions that, as a result, melted to a lesser extent. Models that derived these enclaves from regions of the crust above the zones of partial melting, so that they are not restites, are complex, unnecessary, do not conform with their ubiquity in the more mafic S-type granites, and are not consistent with their chemical compositions. The origin of the microgranular enclaves is controversial. In most S-type granites these enclaves have been recrystallized to a similar mineral assemblage to the host granite with a higher proportion of biotite. In a few places, such material is seen to be forming by recrystallization of material in the core of the enclave, which has the assemblage quartz + calcic plagioclase + orthopyroxene ± cordierite ± biotite with accessory ilmenite, sulfide and apatite. All of the microgranular enclave cores show pseudo-doleritic texture in which calcic plagioclase crystals (> An60) and orthopyroxene crystals project into or are enclosed by quartz. Large plagioclase crystals are zoned, with some core compositions as calcic as An94. The low Na contents of the microgranular enclaves are not consistent with an igneous origin. We consider that these enclaves were derived by metamorphism of calcareous

  4. A hybrid origin for Lachlan S-type granites: the Murrumbidgee Batholith example

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    Healy, B.; Collins, W. J.; Richards, S. W.

    2004-10-01

    The Murrumbidgee Batholith is typical of other composite S-type granite batholiths in the Lachlan Fold Belt (LFB) of southeastern Australia, consisting of discrete peraluminous, cogenetic granite suites. However, it contains a unique suite (Murrumbucka) at its southern extremity that has chemical and petrological features transitional with metaluminous I-type granites. Previous detailed structural and metamorphic studies have shown that the batholith is tilted northward, exposing subvolcanic plutons in the north and root zones in the south, originally located at depths of ˜10 km. A transition from mafic, foliated, sheet-like granites in the south to felsic, generally less foliated, homogeneous granites in the north is consistent with magma ascent via subvertical, structurally controlled sheets to emplacement in an overlying magma chamber. In the inferred root zones, the Murrumbucka Suite hosts migmatitic metasedimentary and gabbroic rocks, both of which have transitional contacts and show evidence for mafic-felsic interaction with the Murrumbucka Suite. The migmatites extend southward to become part of the high- T, low- P Cooma Metamorphic Complex, which contains a core of heterogeneous remobilised diatexitic granite (Cooma Suite), lenses of which also occur throughout the southern (deeper) parts of the Murrumbidgee Batholith. The composition of the most mafic rocks from the batholith lies on a chemical tie-line between Cooma Suite granites and the gabbros, for almost all elements. This chemical coincidence is interpreted to reflect derivation of parental Murrumbidgee S-type granite magmas by bulk mixing between a felsic (crustal) and mafic (mantle-derived) component, consistent with Sr and Nd isotopic results and field observations. Based on the tie-lines and simple numerical modelling, the Murrumbucka suite is estimated to be a 50:50 mix of mantle- and crustal-derived magmas, whereas the more peraluminous and widespread Clear Range Suite, which is very typical

  5. Comparison of oxygen fugacities of S-type granites across the Archean-Proterozoic boundary

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    Bucholz, C. E.; Eiler, J. M.; Stolper, E. M.; Breaks, F. B.

    2016-12-01

    We investigate whether changes in atmospheric O2 levels across the Archean-Proterozoic (AP) boundary were translated into the igneous record via partial melting or assimilation of sedimentary rocks with potentially differing oxidation states. To isolate the effects of sediment melting, we studied 5 S-type granites from the Superior Province (2640-2685 Ma) and 19 from the Paleoproterozoic (PP) Trans-Hudson and Wopmay orogenies (1715-1885 Ma), which were derived from sediments deposited at most 100-400 Ma before subsequent burial and partial melting. Published data from sediment melting experiments indicate that at a fixed temperature, the FeT/Mg ratios of partial melts - and therefore also FeT/Mg in biotites in granites formed from such melts - are sensitive to the abundance of Fe-Ti oxides in the residue. Specifically, FeT/Mg melt and biotite ratios are lower when Fe-Ti oxides are modally important in the residue due to the incorporation of a significant amount of bulk sediment Fe in the oxide phase. In turn, Fe-Ti oxide stability is highly sensitive to the Fe oxidation state inherited from the sedimentary source, being favored at high Fe3+/Fe2+ ratios. Analyzed biotite compositions from the Archean S-type granites have higher FeT/Mg ratios than those from the PP (2.7-3.7 v. 1.6-2.3) and therefore likely reflect more reducing conditions. The simplest explanation of our results is that the Archean S-type granites were derived from more reduced metasedimentary sources relative to the PP S-type granites, being richer in Fe2+-bearing minerals (e.g., pyrite or siderite) and poorer in Fe3+-bearing phases (e.g., magnetite or hematite). The variation in Fe oxidation state of S-type granites across the AP boundary could reflect the effect on sediments of the Great Oxygenation Event that roughly coincides with this boundary. Another possibility is that there is more reduced organic carbon in the sources of the Archean versus PP S-type granites; however, existing data

  6. Metasedimentary melting in the formation of charnockite: Petrological and zircon U-Pb-Hf-O isotope evidence from the Darongshan S-type granitic complex in southern China

    Science.gov (United States)

    Jiao, Shu-Juan; Li, Xian-Hua; Huang, Hui-Qing; Deng, Xi-Guang

    2015-12-01

    Charnockites are Opx-bearing igneous rocks commonly found in high-grade metamorphic terranes. Despite being volumetrically minor, they show a wide range in both bulk geochemistry and intensive parameters. They form a characteristic component of the AMCG (anorthosite-mangerite-charnockite-granite) suite, but their association with typical S-type granites is less well-known. The Darongshan S-type granitic complex (DSGC) in Guangxi Province, southern China, contains granites varying in mafic silicate mineral assemblages from Bt + Crd (Darongshan suite) to Opx + Grt + Bt + Crd (Jiuzhou suite) and Opx + Crd ± Bt (Taima suite), corresponding to a geochemical transition from magnesian calc-alkalic to ferroan calc-alkalic. However, its genesis, even the accurate age of intrusion, remains highly contentious despite intensive research. In order to understand the genesis of charnockite and its genetic relationship with S-type granite; here, we first determined zircon U-Pb ages of each suite using a SIMS on the basis of a detailed petrological study. Zircon U-Pb ages show that all suites of the complex were emplaced contemporaneously at ca. 249 Ma. Monazite apparent U-Pb ages are indistinguishable from zircon U-Pb ages within analytical error. Further in situ zircon Hf-O isotope analyses reveal that the granitic complex was dominantly derived from reduced melting metasedimentary rocks (δ18Ozircon = ca. 11‰; εHf(t)zircon = ca. - 10; Δlog FMQ ≤ 0; Mn in apatite oxybarometer) with rare material input from the mantle. The variation in δ18O (7.8‰-12.9‰) is more likely a result of hybridization, whereas that in εHf(t) (- 31.9 to - 1.8) is a result of both hybridization and disequilibrium melting. The variation in mineralogy and geochemistry may be interpreted as a result of entrainment of peritectic garnets from biotite-dehydration melting. Nevertheless, heat input from mantle through basaltic intrusion/underplating is considered to play a major role in high

  7. Chemical and boron-isotope variations in tourmalines from an S-type granite and its source rocks: the Erongo granite and tourmalinites in the Damara Belt, Namibia

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    Trumbull, R. B.; Krienitz, M.-S.; Gottesmann, B.; Wiedenbeck, M.

    2008-01-01

    Tourmaline is widespread in metapelites and pegmatites from the Neoproterozoic Damara Belt, which form the basement and potential source rocks of the Cretaceous Erongo granite. This study traces the B-isotope variations in tourmalines from the basement, from the Erongo granite and from its hydrothermal stage. Tourmalines from the basement are alkali-deficient schorl-dravites, with B-isotope ratios typical for continental crust (δ11B average -8.4‰ ± 1.4, n = 11; one sample at -13‰, n = 2). Virtually all tourmaline in the Erongo granite occurs in distinctive tourmaline-quartz orbicules. This “main-stage” tourmaline is alkali-deficient schorl (20-30% X-site vacancy, Fe/(Fe + Mg) 0.8-1), with uniform B-isotope compositions (δ11B -8.7‰ ± 1.5, n = 49) that are indistinguishable from the basement average, suggesting that boron was derived from anatexis of the local basement rocks with no significant shift in isotopic composition. Secondary, hydrothermal tourmaline in the granite has a bimodal B-isotope distribution with one peak at about -9‰, like the main-stage tourmaline, and a second at -2‰. We propose that the tourmaline-rich orbicules formed late in the crystallization history from an immiscible Na-B-Fe-rich hydrous melt. The massive precipitation of orbicular tourmaline nearly exhausted the melt in boron and the shift of δ11B to -2‰ in secondary tourmaline can be explained by Rayleigh fractionation after about 90% B-depletion in the residual fluid.

  8. Selective entrainment of peritectic garnet into S-type granitic magmas: Evidence from Archaean mid-crustal anatectites

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    Taylor, Jeanne; Stevens, Gary

    2010-12-01

    Entrainment of restite is commonly invoked to explain both the origin of relatively mafic granites and granodiorites, as well as the chemical connection between granite magmas and their sources. This concept has become linked to models for magma migration out of the source, as restite entrainment is considered to take place when diatexitic sources mobilise en masse. This is at odds with the common occurrence of relatively mafic granites as high level intrusions in the crust or their eruptive equivalents that must have formed from markedly water-undersaturated magmas that ascended through narrow conduits. We investigate pelitic migmatites from the Mkhondo Valley Metamorphic Suite (MVMS) in Swaziland, where a mid-crustal heating event produced metatexitic migmatites with minimal post-anatectic recrystallisation. In these rocks all the garnet is peritectic, having arisen through biotite fluid-absent melting, which produced garnet poikiloblasts characterised by inclusions of melt, quartz and biotite. Leucosomes that represent sites of melt transfer carry similar, smaller (typically accessory phases, while the recrystallised garnet in the larger melt-filled structures became progressively better equilibrated with these minerals. Thus, peritectic garnet in the source grew sufficiently rapidly to prevent trace element equilibrium with the bulk-rock composition, and, concurrent rapid magma segregation prevented the development of diatexitic source conditions. The segregated magma consisted of melt, the peritectic assemblage (principally garnet) and the accessory minerals monazite and zircon. These rocks illustrate that mafic granites may arise purely as mixtures of melt and the peritectic assemblage produced by the incongruent melting reaction. Importantly, under the circumstances which produced the MVMS anatectites, peritectic garnet is entrained as < 1 mm poikiloblasts, demonstrating how mafic granitic magmas can migrate out of the source without the source becoming

  9. Post-orogenic shoshonitic magmas of the Yzerfontein pluton, South Africa: the `smoking gun' of mantle melting and crustal growth during Cape granite genesis?

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    Clemens, J. D.; Buick, I. S.; Frei, D.; Lana, C.; Villaros, A.

    2017-09-01

    The post-orogenic Yzerfontein pluton, in the Saldania Belt of South Africa was constructed through numerous injections of shoshonitic magmas. Most magma compositions are adequately modelled as products of fractionation, but the monzogranites and syenogranites may have a separate origin. A separate high-Mg mafic series has a less radiogenic mantle source. Fine-grained magmatic enclaves in the intermediate shoshonitic rocks are autoliths. The pluton was emplaced between 533 ± 3 and 537 ± 3 Ma (LA-SF-ICP-MS U-Pb zircon), essentially synchronously with many granitic magmas of the Cape Granite Suite (CGS). Yzerfontein may represent a high-level expression of the mantle heat source that initiated partial melting of the local crust and produced the CGS granitic magmas, late in the Saldanian Orogeny. However, magma mixing is not evident at emplacement level and there are no magmatic kinships with the I-type granitic rocks of the CGS. The mantle wedge is inferred to have been enriched during subduction along the active continental margin. In the late- to post-orogenic phase, the enriched mantle partially melted to produce heterogeneous magma batches, exemplified by those that formed the Yzerfontein pluton, which was further hybridised through minor assimilation of crustal materials. Like Yzerfontein, the small volumes of mafic rocks associated with many batholiths, worldwide, are probably also low-volume, high-level expressions of crustal growth through the emplacement of major amounts of mafic magma into the deep crust.

  10. Sedimentology of granite boulder conglomerates and associated clastics in the onshore section of the late Mesozoic Pletmos Basin (Western Cape, South Africa)

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    Bordy, Emese M.; America, Travis

    2016-07-01

    Along the southern margin of South Africa, intermountain rift successions, which comprise unusually large, rounded granite boulders and other coarse clastics, reveal an important geological history about the mid-Mesozoic extensional tectonics that lead to the break-up of Gondwana. These strata, mapped as part of the Mid to Upper Jurassic Enon Formation, allow the assessment of the nature, intensity and mode of sediment transport in onshore section of the Pletmos Basin, which is one of the late Mesozoic basins in southern Africa. Based on sedimentary facies analysis, palaeocurrent measurements and semi-quantitative palaeohydraulic calculations, the results suggest that the abundant coarse sediment was deposited by debris-flows and stream-flow floods on a proximal alluvial fan with high gradient alluvial channels. The floods were intense with mean flow velocity of ˜6 m3/s and peak discharge of ˜450 m3/s. While the role of climate in the sedimentation dynamics remains unknown, syn-sedimentary rift tectonics were likely significant and caused, north of the major boundary fault, the unroofing and denudation of the uplifted mountainous source areas, including the Late Ediacaran-Cambrian Maalgaten Granite Suite and the Siluro-Ordovician Table Mountain Group (Cape Supergroup).

  11. Assessing the isotopic evolution of S-type granites of the Carlos Chagas Batholith, SE Brazil: Clues from U-Pb, Hf isotopes, Ti geothermometry and trace element composition of zircon

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    Melo, Marilane G.; Lana, Cristiano; Stevens, Gary; Pedrosa-Soares, Antônio C.; Gerdes, Axel; Alkmin, Leonardo A.; Nalini, Hermínio A.; Alkmim, Fernando F.

    2017-07-01

    The Carlos Chagas batholith (CCB) is a very large ( 14,000 km2) S-type granitic body formed during the syn-collisional stage of the Araçuaí orogen (southeastern Brazil). Zircons extracted from the CCB record a wide range of U-Pb ages (from 825 to 490 Ma), indicating a complex history of inheritance, magmatic crystallization and partial melting during the evolution of the orogeny. Magmatic zircons (ca. 578-588 Ma) are marked by similar Hf isotope compositions and REE patterns to those of inherited cores (ca. 825-600 Ma), indicating that these aspects of the chemical signature of the magmatic zircons have likely been inherited from the source. The U-Pb ages and initial 176Hf/177Hf ratios from anatectic and metamorphic zircon domains are consistent with a two-stage metamorphic evolution marked by contrasting mechanisms of zircon growth and recrystallization during the orogeny. Ti-in-zircon thermometry is consistent with the findings of previous metamorphic work and indicates that the two metamorphic events in the batholith reached granulite facies conditions (> 800 °C) producing two generations of garnet via fluid-absent partial melting reactions. The oldest metamorphic episode (ca. 570-550 Ma) is recorded by development of thin anatectic overgrowths on older cores and by growth of new anatectic zircon crystals. Both domains have higher initial 176Hf/177Hf values compared to relict cores and display REE patterns typical of zircon that grew contemporaneously with peritectic garnet through biotite-absent fluid partial melting reactions. Hf isotopic and chemical evidences indicate that a second anatectic episode (ca. 535-500 Ma) is only recorded in parts from the CCB. In these rocks, the growth of new anatectic zircon and/or overgrowths is marked by high initial 176Hf/177Hf values and also by formation of second generation of garnet, as indicated by petrographic observations and REE patterns. In addition, some rocks contain zircon crystals formed by solid

  12. Portuguese granites associated with Sn-W and Au mineralizations

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    Ana M.R. Neiva

    2002-01-01

    Full Text Available In northern and central Portugal, there are different tin-bearing granites. Most of them are of S-type, others have mixed characteristics of I-type and S-type granites and a few are of I-type. Tin-tungsten deposits are commonly associated with Hercynian tin-bearing S-type granites. Some quartz veins with wolframite are associated with an I-type granite, which has a low Sn content. In suites of tin-bearing S-type granitic rocks, Sn content increases as a function of the degree of fractional crystallization. Greisenizations of two-mica S-type granites associated with tin-tungsten mineralizations are accompanied by an increase in SiO2, H2O+, Sn, W, Nb, Ta, Rb, Zn, and Pb and decrease in MgO, Na2O, V, Sc,Zr, and Sr. The granite associated with the Jales gold deposit is of S-type and strongly differentiated like the tin-bearing S-type granites, but it has a very low Sn content. During fractional crystallization, Si, Rb, Sn, Pb, Au, As, Sb, and S increase. During increasing degree of hydrothermal alteration of this granite at the gold-quartz vein walls, there are progressive increases in K2O, H2O+, Sn, Cs, Cu, Pb, Au, Sb, As, and S.

  13. 2005 dossier: granite; Dossier 2005: granite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the geologic disposal of high-level and long-lived radioactive wastes in granite formations. Content: 1 - advantage of granitic formations for the geologic disposal; 2 - containers; 3 - design study of a disposal facility in granitic environment; 4 - understanding and modelling of granite; 5 - description of disposal concepts in granitic environment; 6 - long-term and safety aspects; 7 - conclusion. (J.S.)

  14. Magmatic and related mineral deposits of the Pan-African Saldania belt in the Western Cape Province, South Africa

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    Rozendaal, A.; Scheepers, R.

    1995-07-01

    Mineral deposits and prospects of the Pan-African Saldania orogenic belt in the Western Cape Province, South Africa, are reviewed. The polyphase, deformed, low-grade metamorphosed, volcano-sedimentary Malmesbury Group constitutes a complex, poorly understood supracrustal sequence that has been loosely subdivided into the Tygerberg, Swartland and Boland tectono-stratigraphic terranes on the basis of NW-trending fault zones. Syn- and post-tectonic granitoids of the Cape Granite Suite selectively intruded these terranes. Early S-types preferred the Tygerberg terrane, whereas the later I-types dominate the remaining areas. Anorogenic A-type granites, however, occur in all three terranes. Despite the absence of operating base or precious metal mines in the area, this study has established at least four metal associations directly or indirectly related to the intrusions: i) Cassiterite-wolframite (±Au, Cu, Mo, Zn, As, Fe-sulphides) in quartz and quartz/aplite veins hosted by tour-malinized and locally greissenized S-type granite. Similar exo-granitic veins occur in proximal metamorphites; ii) Juxtaposed, disseminated, stockwork breccia and vein style CuMoFe(Au)-sulphide mineralization hosted by mafic- to intermediate-intrusions of high-K calc-alkaline, I-type affinity; iii) CuMoAu-sulphides hosted by hydraulic breccia pipes, stocks and veins occurring in anorogenic A-type alkali feldspar granites and amphibole quartz syenites; iv) Scheelite with minor CuMoAu-sulphides associated with endo- and exo-skams spatially related to I-type monzogranite, granite and alkali feldspar granite. The first three associations occur along the Yzerfontein-Helderberg-zone, a 180 km lineament in the Tygerberg terrane, exploited by syn-, late- and post-tectonic intrusions and their related mineralization. The fourth association is typical of the Boland terrane. The spatial and temporal relationships among the various metal associations are interpreted as the result of

  15. EXPLOITATION OF GRANITE BOULDER

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    Ivan Cotman

    1994-12-01

    Full Text Available The processes of forming, petrography, features, properties and exploitation of granite boulders are described. The directional drilling and black powder blasting is the succesful method in exploitation of granite boulders (boulder technology (the paper is published in Croatian.

  16. Granit, Prof. Ragnar Arthur

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1964 Honorary. Granit, Prof. Ragnar Arthur Nobel Laureate (Medicine) - 1967. Date of birth: 30 October 1900. Date of death: 11 March 1991. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the ...

  17. Petrogenesis of the Late Jurassic peraluminous biotite granites and muscovite-bearing granites in SE China: geochronological, elemental and Sr-Nd-O-Hf isotopic constraints

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    Jiang, Yao-Hui; Zhu, Shu-Qi

    2017-12-01

    : Partial melting of Precambrian metasedimentary rocks (mainly two-mica schist) in the lower crust at temperatures of ca. 820 °C generated the melts of the less felsic biotite granites. Such primary crustal melts underwent biotite-dominant fractionation crystallization, forming the felsic biotite granites. Progressive plagioclase-dominant fractionation crystallization from the evolved biotite granites produced the more felsic muscovite-bearing granites. Thus, the biotite granites belong to the S-type whereas the muscovite-bearing granites are highly fractionated S-type granites. We further suggest that during the formation of the muscovite-bearing granites the fractional crystallization was accompanied by fluid fractionation and most likely the addition of internally derived mineralizing fluids. That is why the large-scale polymetallic mineralization is closely related to the muscovite-bearing granites rather than biotite granites in SE China. This is important to further understand the source and origin of biotite granites and muscovite-bearing granites in SE China even worldwide.

  18. Geochemistry of Pegmatites associated with the cape coast granite ...

    African Journals Online (AJOL)

    Lower values of molar CaO/ (MgO + FeO tot) coupled with higher values of molar Al2O3/(MgO + FeOtot) suggest their derivation from partial melting from metapelitic sources, with the Birimian metasedimentary rocks being the likely source material. The rocks are depleted ...

  19. Cape Town

    African Journals Online (AJOL)

    2Centre of Allied Health Research, University of South Australia, Adelaide. 3Department of Human Biology, University of Cape Town. Abstract. Objective. The objective of this study was to ascertain. , the currentknee injury prevalence among young bas-. ' ' e, * apeTown. _ 7 , . “ctivelsurvey wasconducted ' lOHHOHlHjUITSS ...

  20. Cape Verde

    Science.gov (United States)

    2007-01-01

    This Mars Exploration Rover Opportunity Pancam 'super resolution' mosaic of the approximately 6 m (20 foot) high cliff face of the Cape Verde promontory was taken by the rover from inside Victoria Crater, during the rover's descent into Duck Bay. Super-resolution is an imaging technique which utilizes information from multiple pictures of the same target in order to generate an image with a higher resolution than any of the individual images. Cape Verde is a geologically rich outcrop and is teaching scientists about how rocks at Victoria crater were modified since they were deposited long ago. This image complements super resolution mosaics obtained at Cape St. Mary and Cape St. Vincent and is consistent with the hypothesis that Victoria crater is located in the middle of what used to be an ancient sand dune field. Many rover team scientists are hoping to be able to eventually drive the rover closer to these layered rocks in the hopes of measuring their chemistry and mineralogy. This is a Mars Exploration Rover Opportunity Panoramic Camera image mosaic acquired on sols 1342 and 1356 (November 2 and 17, 2007), and was constructed from a mathematical combination of 64 different blue filter (480 nm) images.

  1. Status of LLNL granite projects

    Energy Technology Data Exchange (ETDEWEB)

    Ramspott, L.D.

    1980-12-31

    The status of LLNL Projects dealing with nuclear waste disposal in granitic rocks is reviewed. This review covers work done subsequent to the June 1979 Workshop on Thermomechanical Modeling for a Hardrock Waste Repository and is prepared for the July 1980 Workshop on Thermomechanical-Hydrochemical Modeling for a Hardrock Waste Repository. Topics reviewed include laboratory determination of thermal, mechanical, and transport properties of rocks at conditions simulating a deep geologic repository, and field testing at the Climax granitic stock at the USDOE Nevada Test Site.

  2. Granites petrology, structure, geological setting, and metallogeny

    CERN Document Server

    Nédélec, Anne; Bowden, Peter

    2015-01-01

    Granites are emblematic rocks developed from a magma that crystallized in the Earth’s crust. They ultimately outcrop at the surface worldwide. This book, translated and updated from the original French edition Pétrologie des Granites (2011) is a modern presentation of granitic rocks from magma genesis to their crystallization at a higher level into the crust. Segregation from the source, magma ascent and shapes of granitic intrusions are also discussed, as well as the eventual formation of hybrid rocks by mingling/mixing processes and the thermomechanical aspects in country rocks around granite plutons. Modern techniques for structural studies of granites are detailed extensively. Granites are considered in their geological spatial and temporal frame, in relation with plate tectonics and Earth history from the Archaean eon. A chapter on granite metallogeny explains how elements of economic interest are concentrated during magma crystallization, and examples of Sn, Cu, F and U ore deposits are presented. Mi...

  3. MORPHOMETRY OF ZIRCON FROM BETLIAR GRANITE

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    Jakabská Katarína

    1997-10-01

    Full Text Available Morphometrical analyse has been provided, using the method of [10] , on zircon from granite porphyry at Betliar. The result of this investigation indicate a comagmatic origin of Betliar and other granite bodies in the Gemericum. The source materila for at the granite magma formation originated by hybridization of crust-mantle rocks.

  4. Thermal expansion behaviour of granites

    Czech Academy of Sciences Publication Activity Database

    Plevová, Eva; Vaculíková, Lenka; Kožušníková, Alena; Ritz, M.; Simha Martynková, G.

    2016-01-01

    Roč. 123, č. 2 (2016), s. 1555-1561 ISSN 1388-6150 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : thermomechanical analysis * differential thermal analysis * granites Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.953, year: 2016 http://link.springer.com/article/10.1007/s10973-015-4996-z

  5. Progressive silicosis in granite workers

    Science.gov (United States)

    Gründorfer, W.; Raber, A.

    1970-01-01

    Gründorfer, W., and Raber, A.(1970).Brit. J. industr. Med.,27, 110-120. Progressive silicosis in granite workers. The first case of silicosis was discovered in a granite quarry and crushing plant in Lower Austria in 1958 after 30 years of freedom. A routine ϰ-ray survey then revealed no further cases but three more cases were discovered in the next two years. Detailed investigation revealed that these and further cases came from the area where the granite was crushed and loaded. In 10 years 18 cases were found out of a labour force of 170 falling to 120. Average exposure was 15 years and the disease tended to progress. Fifteen of the 18 cases came from the crushing plant where only 20 men were at risk, indicating a very high incidence within 15 years of first exposure. The risk is attributed to increased size and working capacity of the machines without improved dust suppression. This had led to dust levels over 10 times the accepted maximum in places. As well as more effective dust suppression, a reduction in staff, the wearing of masks and effective medical supervision of those particularly at risk are recommended. Images PMID:5428630

  6. Cape Kennedy Thunderstorms Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Cape Kennedy Thunderstorms Data contains an account of all thunderstorms reported in weather observations taken at Cape Kennedy Air Force Station, Florida between...

  7. Composition of coexisting zircon and xenotime in rare-metal granites from the Krušné Hory/Erzgebirge Mts. (Saxothuringian Zone, Bohemian Massif)

    Science.gov (United States)

    René, Miloš

    2014-08-01

    Zircon and xenotime, from two mineralogically and chemically contrasting granite suites occurring in the Krušné Hory/Erzgebirge Mts., display extended compositional variability with respect to abundances of Zr, Hf, REE, Y, P, Th, Ca, Al, Fe and As. According to their geochemical signatures, P-rich (S-type) and P-poor (A-type) granites could be distinguished here. Both granite suites display high Ga/Al ratios (>2.6) and according to FeOtot./(FeOtot. + MgO) ratio can be classified as ferrous granites. Consequently, the both ratios cannot be used for discrimination S- and A-type granites. Both minerals are characterized by a variety of complex zircon-xenotime textures. They are usually strong hydrated and enriched in F. Zircon from P-rich granites displays a significant enrichment in P (up 0.24 apfu P), whereas zircon from P-poor granites has lower P and higher Y (up to 0.15 apfu Y). The xenotime-type substitution is the most important mechanism of isomorphic substitution in zircon in both granite suites. Zircon from both granite suites is typically enriched in Hf, especially unaltered zircon from P-rich granites (up to 8.2 wt. % HfO2). However in altered zircons the Hf/Zr ratio is higher in the P-poor granites. The Hf-rich zircon from unaltered P-rich granite crystallised from low temperature granite melt, whereas altered zircons crystallised during post-magmatic hydrothermal alteration (greisenization). Xenotime from P-poor granites displays a considerable enrichment in HREE (up to 40 mol. % HREEPO4) compared to xenotime from P-rich granites (up to 20 mol. % HREEPO4). Xenotime compositions from P-rich granites are influenced by brabantite-type substitution, whereas for xenotime from P-poor granites the huttonite-type substitution is dominant. Unusual enrichments in HREE is significant for xenotime from P-poor granites, especially in Yb (up to 0.17 apfu Yb) and Dy (up to 0.11 apfu).

  8. Characterization of weathering profile in granites and ...

    Indian Academy of Sciences (India)

    Therefore, we propose three models describing the weathering profiles in granites, metasediments, and volcanic rocks for hard rock formations located in West Africa. For each of these models proposed for granitic and volcano sedimentary rocks of the Dimbokro catchment, vertical layered weathering profiles are described, ...

  9. Les Granites des Complexes Annulaires

    Science.gov (United States)

    Bowden, Peter

    This book, Manual and Methods 4, published by France's BRGM, together with a mouthwatering preface by R. Black promises much for the student of ring complexes. It consists of four distinct chapters, each divided into a number of subsections, with 52 text figures and 9 tables. Although in reality it is based on a doctoral dissertation concerned with the newly discovered ring structures in Corsica, it is spiced with references to past and present research in Nigeria, and observations from French expeditions to the Kerguelen Islands. There are also brief commentaries on the author's observations in New Hampshire and Massachusetts. The text effectively represents a distillation of knowledge concerned with oversaturated alkaline magmatism in continental and oceanic settings. The book has a good bibliography with English-language scientific literature references up to 1980. While aware that ring-complex compositions can be variable, ranging from calc-alkaline to alkaline, the author restricts his writings to granitic and related rocks of the alkaline and peralkaline spectrum.

  10. Formation of Hadean granites by melting of igneous crust

    Science.gov (United States)

    Burnham, A. D.; Berry, A. J.

    2017-06-01

    The oldest known samples of Earth, with ages of up to 4.4 Gyr, are detrital zircon grains in meta-sedimentary rocks of the Jack Hills in Australia. These zircons offer insights into the magmas from which they crystallized, and, by implication, igneous activity and tectonics in the first 500 million years of Earth’s history, the Hadean eon. However, the compositions of these magmas and the relative contributions of igneous and sedimentary components to their sources have not yet been resolved. Here we compare the trace element concentrations of the Jack Hills zircons to those of zircons from the locality where igneous (I-) and sedimentary (S-) type granites were first distinguished. We show that the Hadean zircons crystallized predominantly from I-type magmas formed by melting of a reduced, garnet-bearing igneous crust. Further, we propose that both the phosphorus content of zircon and the ratio of phosphorus to rare earth elements can be used to distinguish between detrital zircon grains from I- and S-type sources. These elemental discriminants provide a new geochemical tool to assess the relative contributions of primeval magmatism and melting of recycled sediments to the continents over geological time.

  11. Cape Kennedy Tower Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digitized data taken from original weather observations taken at Cape Kennedy Air Force Station, Florida. Elements recorded are wind speed and direction, wind speed...

  12. Cape Kennedy Weather Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digitized data taken from original weather observations taken at Cape Kennedy Air Force Station, Florida. Elements recorded are wind speed and direction,...

  13. Cape Peirce field report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The 1988 Cape Peirce season ran from June 16th to October 14th with volunteers Donna O'Daniel, Gay Sheffield, and, later in the season, Michelle Bourassa stationed...

  14. Rare metal granites and related rocks of the Ukrainian shield

    Directory of Open Access Journals (Sweden)

    Esipchuk, K.Ye.

    1993-12-01

    Full Text Available Two rare metal leucocratic granites, Perga and Kamennaya complexes, can be distinquished on the Ukrainian shield. The Perga complex consists of medium- and coarse grained, mainly porphyric, biotite, riebeckite and aegirine granites, granite porphyries, microclinites and albitites with rare metal mineralization (genthelvite, phenacite, tantalite, cassiterite and wolframite etc.. Granites from several stocks (up to 30 km2 in the northwestern part of the shield, situated along the fracture zone, restricted the large Korosten pluton of rapakivi granites to the northwest. The age of these granites (Pb-Pb and U-Pb methods on zircon and monazite practically coincide with the age of rapakivi granites being 1750 Ma. Within the Korosten complex of rapakivi granites we consider that zinnwaldite granites, which are characterized by fluorite and topazine mineralization, represent the final phase of pluton. These granites differ from the Perga ones by their low content of rare metals. The Kamennaya Mogila complex lies in the southeastern part of the Ukrainian shield. It consists of biotite and muscovite-biotite, medium- and coarse-grained (also porphyric, and occasionally greisining granites with rare metal mineralization (cassiterite, columbite, molybdenite, wolframite and beryl. Granites form several stocks (5-30 km2 situated 10-30 km to the west-northwest of the South-Kalchik gabbro-syenite-granite pluton. Granitoids in both of these complexes have similar isotopic ages (1800 Ma. Leucocratic subalkaline granites (the Novoyanisol type are known within the pluton itself, occupying an intermediate position between the above mentioned in terms of mineral and geochemical composition. The gabbro-syenite-granite formation of the Nearazov region has a substantial similarity to the anorthosite-rapakivi-granite formation. In this respect the relation of each of them to rare metal granites is rather remarkable. This relation is, most probably, not only spatial, but

  15. PREVALENCE OF METABOLIC SYNDROME IN GRANITE WORKERS

    Directory of Open Access Journals (Sweden)

    Srilakshmi

    2015-10-01

    Full Text Available BACKGROUND: The prevalence of the metabolic syndrome (MS has significantly increased over the last few decades and has become a main health challenge worldwide. Prevalence of MS is quickly rising in developing countries due to changing lifestyle. It was considered worthwhile to study MS and its components in granite workers since granite factories are situated in and around Khammam area. Moreover, no studies of MS in granite workers have been reported in literature. OBJECTIVES: Aim of our study is to assess the prevalence of metabolic syndrome and its components in granite workers. MATERIALS AND METHODS: 210 male workers in the age group of 20 - 50 working in granite industries located in and around the Khammam town of Telangana State are selected for the present study. Blood pressures (BP, waist circumference (WC were measured. Fasting blood samples were collected for the estimation of glucose and lipids. RESULTS: 69 subjects out of 210 were identified as having MS based on updated National cholesterol education programme - Adult Treatment Panel III (NCEP - ATP III guidelines. CONCLUSION: MS should be identified and remedial measures may be suggested, so that the risk of hypertension, cardiovascular risk, diabetes and the resultant morbidity is minimized and can be delayed

  16. Mesozoic Granitic Magmatism in Macao, Southeast China

    Science.gov (United States)

    Quelhas, P. M.; Mata, J.; Lou, U. T.; Ribeiro, M. L.; Dias, Á. A.

    2016-12-01

    Macao ( 30 Km2) is a territory characterized by small granitic intrusions, located along the coastal region of Southeast China (Cathaysia Block). Granitoids occur as different facies, including microgranite dykes, with distinct textural, mineralogical and geochemical features, for which a middle-upper Jurassic age ( 164 Ma) has been proposed. New data suggest that these granitoids are mostly high-K calc-alkaline metaluminous (A/CNK = 0.8 - 1.1) biotite granites, consistent with total absence of primary muscovite. They show variable amounts of SiO2 (67-77%), reflecting different degrees of magmatic evolution. There is also variability in terms of trace elements, particularly Rare Earth Elements (REEs), evidenced by decreasing (La/Sm)N, (Gd/Lu)N, (Ce/Yb)N and (Eu/Eu*)N towards the more evolved samples, which can be partly attributed to fractional crystallization processes. Most of the granitoids are characterized by (La/Yb)N = 3 - 10.8, showing negative Ba, Nb, Sr, Zr, P, Ti and Eu anomalies. On the other hand, microgranite dykes, along with a few more evolved granites, show an opposite tendency, being usually enriched in HREEs relatively to LREEs with (La/Yb)N = 0.4 - 1.1. Our data suggests intermediate genetic affinities between I-type and A-type granites. Although these granitoids are mostly metaluminous (characteristic of I-types), Ga/Al ratios, usually used to identify A-types, are close to the accepted boundary between A-type and other granite types. The affinities with A-type granites are more marked for the more evolved facies, which depict higher values of FeOt/MgO (14 - 60) and K2O/MgO (60 - 250). Their trace element characteristics are also transitional between WPG (Within-plate granites) and Syn-COLG (Collision Granites). We interpret those transitional characteristics (A/I and WPG/Syn-COLG) of Macao granitoids as reflecting an origin by melting of infracrustal sources over a period of high heat transfer from mantle to crust during an extensional tectonic

  17. High-spatial resolution SIMS U-Pb zircon dating on Malay tin granites: New insights to crustal evolution of the Malaysian Peninsula

    Science.gov (United States)

    Ng, S.; Searle, M. P.; Whitehouse, M. J.; Chung, S.; Robb, L. J.; Ghani, A. A.; Sone, M.

    2012-12-01

    The Southeast Asian tin granite province has previously been recognized as comprising three distinct granitic belt (Cobbing et al., 1986): (1) Middle Permian - Late Triassic Eastern Province with mainly subduction-related I-type granites associated with Cu-Au deposits, (2) Late Permian - Early Jurassic Main Range Province with mainly S-type granites associated with Sn-W deposits, and (3) Late Triassic - Cretaceous Western Province with mixed I- and S-type granites associated with Sn-W deposits. These ages were obtained mainly using whole rock Rb-Sr and K-Ar geochronology in the 70s and 80s, methods that are no longer considered suitable for obtaining crystallization ages of granites due to unstable behaviour of these isotopes in hydrothermal systems. During 2011 we collected over 50 samples of granites across all three zones in Northern Malaysia for U-Pb dating using high-spatial resolution precision SIMS at the Swedish Museum of Natural History. The results reveal a westward younging trend across the Malay Peninsula. The Eastern Province hornblende- and biotite-granites in Eastern Malaysia formed by subduction-related processes have ages lying between 220-285 Ma. The Main Range Province dominantly S-type granites in west and central Malaysia have ages lying between 206-226 Ma. These include dominantly biotite granites with less common tourmaline+biotite leucocratic granites related to crustal thickening processes following collision of Sibumasu with Indochina and closing of the Palaeo-Tethyan Bentong-Raub suture zone. Some enigmatic young Cretaceous zircon rim ages (c. 81-80 Ma) may indicate a young hydrothermal - metasomatic origin for some tin mineralization from both the Eastern Province (Tioman Island) and the Western province (Phuket, Thailand) (Searle et al., 2012). Granites in Malaysia cannot be simply categorized as I-, S- or A-type as most of them failed to show distinctive minerals for classification and there is considerable overlap in geochemical

  18. Tectonic imprints within a granite exposed near Srinagar, Rajasthan ...

    Indian Academy of Sciences (India)

    Partial melting in the middle to lower crustal level produces melts of granitic composition during orogeny. Thrusts play a vital role in their exhumation after consolidation of these granitic melts. In this paper we focus on one such granite along the eastern margin of the Delhi Fold Belt (DFB) rocks near Srinagar, Rajasthan, ...

  19. Characterization of weathering profile in granites and ...

    Indian Academy of Sciences (India)

    be distinguished by the physical, chemical, min- eralogical, geodynamical, and palaeomorphologi- cal features (Geirnaert et al. 1984; Wright 1992;. Freyssinet and Farah 2000; Taylor and Howard. 2000; Dewandel et al. 2006). Most of the proposed weathering profile mod- els concern granitic rocks. Few investigations, e.g.,.

  20. Physics of the granite sphere fountain

    NARCIS (Netherlands)

    Snoeijer, Jacobus Hendrikus; van der Weele, J.P.

    2014-01-01

    A striking example of levitation is encountered in the “kugel fountain” where a granite sphere, sometimes weighing over a ton, is kept aloft by a thin film of flowing water. In this paper, we explain the working principle behind this levitation. We show that the fountain can be viewed as a giant

  1. The global age distribution of granitic pegmatites

    Science.gov (United States)

    McCauley, Andrew; Bradley, Dwight C.

    2014-01-01

    An updated global compilation of 377 new and previously published ages indicates that granitic pegmatites range in age from Mesoarchean to Neogene and have a semi-periodic age distribution. Undivided granitic pegmatites show twelve age maxima: 2913, 2687, 2501, 1853, 1379, 1174, 988, 525, 483, 391, 319, and 72 Ma. These peaks correspond broadly with various proxy records of supercontinent assembly, including the age distributions of granites, detrital zircon grains, and passive margins. Lithium-cesium-tantalum (LCT) pegmatites have a similar age distribution to the undivided granitic pegmatites, with maxima at 2638, 1800, 962, 529, 485, 371, 309, and 274 Ma. Lithium and Ta resources in LCT pegmatites are concentrated in the Archean and Phanerozoic. While there are some Li resources from the Proterozoic, the dominantly bimodal distribution of resources is particularly evident for Ta. This distribution is similar to that of orogenic gold deposits, and has been interpreted to reflect the preservation potential of the orogenic belts where these deposits are formed. Niobium-yttrium-fluorine (NYF) pegmatites show similar age distributions to LCT pegmatites, but with a strong maximum at ca. 1000 Ma.

  2. Landslides and the weathering of granitic rocks

    Science.gov (United States)

    Philip B. Durgin

    1977-01-01

    Abstract - Granitic batholiths around the Pacific Ocean basin provide examples of landslide types that characterize progressive stages of weathering. The stages include (1) fresh rock, (2) corestones, (3) decomposed granitoid, and (4) saprolite. Fresh granitoid is subject to rockfalls, rockslides, and block glides. They are all controlled by factors related to...

  3. Intensive low-temperature tectono-hydrothermal overprint of peraluminous rare-metal granite: a case study from the Dlhá dolina valley (Gemericum, Slovakia

    Directory of Open Access Journals (Sweden)

    Breiter Karel

    2015-02-01

    Full Text Available A unique case of low-temperature metamorphic (hydrothermal overprint of peraluminous, highly evolved rare-metal S-type granite is described. The hidden Dlhá dolina granite pluton of Permian age (Western Carpathians, eastern Slovakia is composed of barren biotite granite, mineralized Li-mica granite and albitite. Based on whole-rock chemical data and evaluation of compositional variations of rock-forming and accessory minerals (Rb-P-enriched K-feldspar and albite; biotite, zinnwaldite and di-octahedral micas; Hf-(Sc-rich zircon, fluorapatite, topaz, schorlitic tourmaline, the following evolutionary scenario is proposed: (1 Intrusion of evolved peraluminous melt enriched in Li, B, P, F, Sn, Nb, Ta, and W took place followed by intrusion of a large body of biotite granites into Paleozoic metapelites and metarhyolite tuffs; (2 The highly evolved melt differentiated in situ forming tourmaline-bearing Li-biotite granite at the bottom, topaz-zinnwaldite granite in the middle, and quartz albitite to albitite at the top of the cupola. The main part of the Sn, Nb, and Ta crystallized from the melt as disseminated cassiterite and Nb-Ta oxide minerals within the albitite, while disseminated wolframite appears mainly within the topaz-zinnwaldite granite. The fluid separated from the last portion of crystallized magma caused small scale greisenization of the albitite; (3 Alpine (Cretaceous thrusting strongly tectonized and mylonitized the upper part of the pluton. Hydrothermal low-temperature fluids enriched in Ca, Mg, and CO2 unfiltered mechanically damaged granite. This fluid-driven overprint caused formation of carbonate veinlets, alteration and release of phosphorus from crystal lattice of feldspars and Li from micas, precipitating secondary Sr-enriched apatite and Mg-rich micas. Consequently, all bulk-rock and mineral markers were reset and now represent the P-T conditions of the Alpine overprint.

  4. Strain in Archean Granite-Greenstone terrains

    Science.gov (United States)

    Robin, C. M.; Bailey, R. C.

    2009-12-01

    A long-standing problem in Archean tectonics is the mode of origin of granite-greenstone belts. Based on structural and morphological similarities to salt domes and Rayleigh-Taylor structures, diapirism has long been an obvious but controversial candidate, as it implies the operation of vertical tectonics in the Archean. Current strain patterns are one of the few field observables available to test hypotheses about the kinematic history of granite-greenstone belts. Previous laboratory (Dixon & Summers, 1983) and numerical (Mareschal & West, 1980) experiments which have been used to predict strain in diapiric structures may not be realistic because of the lack of large thermally activated viscosity contrasts in these models. We have numerically modeled temperature-dependent, non-Newtonian visco-elastic solid-state diapirism under conditions appropriate to Archean crust (Robin & Bailey, 2009). Here we present analyses of strain derived from these models. Our results show important differences from those of previous modelers. These include the formation of narrow high strain zones in the greenstone at the batholith contact and in the axis of the keel, with a low-strain zone between the two, as well as only very small strains in the batholith itself. This suggests that strain recorded in the granitic domes of granite-greenstone terrains must be unrelated to the diapiric overturn mechanism. Our strain analyses should be useful for comparison with published and future field observations, and provide a basis for the interpretation of strain in these ubiquitous Archean structures. Principle strain directions for an evolved diapir resulting from an altered basaltic crust deposited over a granitic basement. Viscosities are temperature- and stress-dependent and viscoelastic.

  5. on the Cape Peninsula

    African Journals Online (AJOL)

    London: Smith, Elder. SMITH, M A 1943. The FaUlUl of British India,. Ceylon and Burma. Reptilia and Amphibia. 3. Serpentes. London: Taylor & Francis. WALL, F 1921. Snakes of Ceylon. Colombo: Gov. Printer. TABLE I. Details of specimens of Typhlops braminus collected in the vicinity of Cape Town. Length and diameter.

  6. Assessment of radiological hazard of commercial granites from Extremadura (Spain).

    Science.gov (United States)

    Guillén, J; Tejado, J J; Baeza, A; Corbacho, J A; Muñoz, J G

    2014-06-01

    The term "commercial granite" comprises different natural stones with different mineralogical components. In Extremadura, western Spain, "commercial granites" can be classified in three types: granite s.s. (sensus stricti), granodiorite, and diorite. The content of naturally occurring radionuclides depended of the mineralogy. Thus, the (40)K content increased as the relative content of alkaline feldspar increased but decreased as the plagioclase content increased. The radioactive content decreased in the following order: granite s.s. > granodiorite > diorite. In this work, the radiological hazard of these granites as building material was analyzed in terms of external irradiation and radon exposure. External irradiation was estimated based on the "I" index, ranged between 0.073 and 1.36. Therefore, these granites can be use as superficial building materials with no restriction. Radon exposure was estimated using the surface exhalation rates in polished granites. The exhalation rate in granites depends of their superficial finishes (different roughness). For distinct mechanical finishes of granite (polish, diamond sawed, bush-hammered and flamed), the surface exhalation rate increased with the roughness of the finishes. Thermal finish presented the highest exhalation rate, because the high temperatures applied to the granite may increase the number of fissures within it. The exhalation rates in polished granites varied from 0.013 to 10.4 Bq m(-2) h(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Geochemical constraints on the source nature and melting conditions of Triassic granites from South Qinling in central China

    Science.gov (United States)

    Lu, Ying-Hui; Zhao, Zi-Fu; Zheng, Yong-Fei

    2016-11-01

    Hf (t) values of - 13.1 to - 2.0, with two-stage Nd-Hf model ages of Mesoproterozoic to Paleoproterozoic. Their εNd (t) values are comparable with those for sedimentary rocks in the southern margin of the South Qinling zone and the northern margin of the South China Block, suggesting a genetic link between them. Therefore, the GTS and HY granites originated from the sedimentary rocks rather than igneous rocks, and thus belong to S-type rather than I-type. It is inferred that these sedimentary rocks were subducted to the lower crustal depth during the Late Triassic collisional orogeny in the Qinling orogen for partial melting to produce the S-type granites.

  8. The anatectic effect on the zircon Hf isotope composition of migmatites and associated granites

    Science.gov (United States)

    Chen, Yi-Xiang; Gao, Peng; Zheng, Yong-Fei

    2015-12-01

    Zircon Hf isotope composition is widely used to trace the growth and evolution of continental crust. However, it is controversial whether the Hf isotope composition of magmatic zircons can faithfully reflect that of their sources, especially for S-type granites. In order to provide an insight into this issue, we have revisited the published Lu-Hf isotope data of zircons from well-studied migmatites and associated granites in the Sulu orogen and the Cathaysian terrane, respectively. The results show greatly elevated 176Hf/177Hf ratios (by more than 10ε units) for newly grown zircon domains compared to the relict zircon domains. This indicates considerable contributions from non-zircon Hf to anatectic melts during crustal anatexis and subsequent magmatism. Furthermore, this more radiogenic Hf isotope signature was not erased during magmatic processes such as crystal fractionation during melt ascent and emplacement. The budget of Hf isotopes in source rocks with respect to mineral Lu/Hf ratios suggests the involvement of Hf-bearing major minerals in anatectic reactions by dissolving Hf-bearing major minerals into the anatectic melts. The significant Hf isotope variations in some anatectic and magmatic zircon domains from the migmatites and granites suggest not only the source heterogeneity but also the variable non-zircon Hf contributions. As such, the Hf isotope compositions of anatectic and magmatic zircons are substantially dictated by the mass balance between the non-zircon Hf from anatectic reactions and the zircon-Hf from the dissolution of protolith zircons into the anatectic melts. They are primarily controlled by P-T conditions and mechanism of crustal anatexis, and the magmatic processes during melt evolution. The present study highlights the important contribution of non-zircon Hf to the anatectic and magmatic zircon domains. In this regard, the greatly elevated 176Hf/177Hf ratios for newly grown zircon domains in the migmatites and granites cannot reflect

  9. Late Triassic post-collisional granites related to Paleotethyan evolution in SE Thailand: Geochronological and geochemical constraints

    Science.gov (United States)

    Qian, Xin; Feng, Qinglai; Wang, Yuejun; Zhao, Tianyu; Zi, Jian-Wei; Udchachon, Mongkol; Wang, Yukun

    2017-08-01

    A set of new U-Pb geochronological, elemental and Sr-Nd-Hf isotopic data is presented to constrain the formation age and petrogenesis of granites in SE Thailand, which are significant for understanding eastern Paleotethyan tectonic evolution and regional correlation in SE Asia. Six granite samples from the Chonburi, Rayong-Bang Lamung and Chanthaburi plutons yielded similar crystallization ages of 222-218 Ma. These granites can be geochemically classified into S-type (Group 1) and I-type (Group 2) granites. Both groups have similar chondrite-normalized REE and primitive mantle-normalized multi-element patterns but distinctly different Sr-Nd-Hf isotopic compositions. Group 1 is characterized by more enriched initial 87Sr/86Sr (i) ratios (0.7101-0.7272) and lower εNd (t) values (- 12.0 to - 13.2) compared with those of Group 2 with 87Sr/86Sr (i) of 0.7027-0.7053 and εNd (t) of - 0.6 to - 1.2. Consistently, zircons from Group 1 yield negative εHf (t) values of - 7.3 to - 27.4 and Mesoproterozoic or older Hf model ages (TDM = 1.53-2.63 Ga), distinct from those of Group 2 with positive εHf (t) values (+ 5.0-+11.3) and younger TDM (0.42-0.67 Ga). Group 1 granites mainly originated from ancient greywackes but Group 2 from juvenile mafic crust with the input of meta-sedimentary component. These data, along with available observations, synthetically indicate that these granites formed in the post-collisional gravitational collapse setting of the thickened crust in response to the assemblage of the Indochina with Sibumasu blocks. They linked northerly and easterly to the Late Triassic granitoids in NW Thailand and East Malay Peninsula related to the Paleotethyan tectonic regime, respectively.

  10. Preface to special issue: Granite magmatism in Brazil

    Science.gov (United States)

    Janasi, Valdecir de Assis; de Pinho Guimarães, Ignez; Nardi, Lauro Valentim Stoll

    2016-07-01

    Granites are important both to the geologic evolution and to the economy of Brazil. Deposits of precious and rare metals, such as Au, Sn and many others, are directly or indirectly associated with granites, especially in the geologically under-explored Amazon region. On the opposite eastern side of the country, expanding exploitation of natural granite as dimension stone makes Brazil currently the world's second largest exporter of granite blocks. Granites are a major constituent of the Brazilian Archean-Proterozoic cratonic domains (the Amazon and São Francisco cratons) and their surrounding Neoproterozoic fold belts. The granites are thus fundamental markers of the major events of crustal generation and recycling that shaped the South American Platform. As a result, Brazilian granites have received great attention from the national and international community, and a number of influential meetings focused on the study of granites were held in the country in the last three decades. These meetings include the two International Symposia on Granites and Associated Mineralization (Salvador, January 21-31, 1987, and August 24-29, 1997), the Symposium on Rapakivi Granites and Related Rocks (Belém, August 2-5, 1995) and the Symposium on Magmatism, Crustal Evolution, and Metallogenesis of the Amazonian Craton (Belém, August 2006). Special issues dedicated to contributions presented at these meetings in the Journal of South American Earth Sciences (Sial et al., 1998), Lithos (Stephens et al., 1999), Canadian Mineralogist (Dall'Agnol and Ramo, 2006), Precambrian Research (Ramo et al., 2002) and Anais da Academia Brasileira de Ciências (Dall'Agnol and Bettencourt, 1997; Sial et al., 1999a) are still important references on the knowledge of Brazilian granites and granite petrology in general.

  11. Properties and CAPE

    DEFF Research Database (Denmark)

    Gani, Rafiqul; O'Connell, J.P.

    2001-01-01

    The role of properties in the solution of Computer Aided Process Engineering (CAPE) problems is described in terms of current trend, future challenges and important issues. Three distinct roles of properties in CAFE have been identified - a service role, a service plus advice role and a service......, advice plus solve role. The CAFE problems solved under each of these roles are described together with simple illustrative examples. Finally, the paper describes how some of the future problems related to integration of synthesis, design and control might be dealt with efficiently and reliably through co......-operative CAFE and properties methodologies. (C) 2001 Elsevier Science Ltd. All rights reserved....

  12. Characterization of Climax granite ground water

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, D.; Harrar, J.; Raber, E.

    1982-08-01

    The Climax ground water fails to match the commonly held views regarding the nature of deep granitic ground waters. It is neither dilute nor in equilibrium with the granite. Ground-water samples were taken for chemical analysis from five sites in the fractured Climax granite at the Nevada Test Site. The waters are high in total dissolved solids (1200 to 2160 mg/L) and rich in sodium (56 to 250 mg/L), calcium (114 to 283 mg/L) and sulfate (325 to 1060 mg/L). Two of the samples contained relatively high amounts of uranium (1.8 and 18.5 mg/L), whereas the other three contained uranium below the level of detection (< 0.1 mg/L). The pH is in the neutral range (7.3 to 8.2). The differences in composition between samples (as seen in the wide range of values for the major constituents and total dissolved solids) suggest the samples came from different, independent fracture systems. However, the apparent trend of increasing sodium with depth at the expense of calcium and magnesium suggests a common evolutionary chemical process, if not an interconnected system. The waters appear to be less oxidizing with depth (+ 410 mV at 420 m below the surface vs + 86 mV at 565 m). However, with Eh measurements on only two samples, this correlation is questionable. Isotopic analyses show that the waters are of meteoric origin and that the source of the sulfate is probably the pyrite in the fracture-fill material. Analysis of the measured water characteristics using the chemical equilibrium computer program EQ3 indicates that the waters are not in equilibrium with the local mineral assemblage. The solutions appear to be supersaturated with respect to the mineral calcite, quartz, kaolinite, muscovite, k-feldspar, and many others.

  13. GRANITE CHIEF WILDERNESS STUDY AREA, CALIFORNIA.

    Science.gov (United States)

    Harwood, David S.; Federspiel, Francis E.

    1984-01-01

    The Granite Chief Wilderness study area encompasses 57 sq mi near the crest of the Sierra Nevada 6 mi west of Tahoe City, California. Geologic, geochemical, and mines and prospect studies were carried out to assess the mineral-resource potential of the area. On the basis of the mineral-resource survey, it is concluded that the area has little promise for the occurrence of precious or base metals, oil, gas, coal, or geothermal resources. Sand, gravel, and glacial till suitable for construction materials occur in the area, but inaccessability and remoteness from available markets preclude their being shown on the map as a potential resource.

  14. Characterization of mechanical damage in granite

    Directory of Open Access Journals (Sweden)

    Minh-Phong Luong

    2014-01-01

    Full Text Available This paper aims to illustrate the use of infrared thermography as a non-destructive and non-contact technique to observe the phenomenological manifestation of damage in granite under unconfined compression. It allows records and observations in real time of heat patterns produced by the dissipation of energy generated by plasticity. The experimental results show that this technique, which couples mechanical and thermal energy, can be used for illustrating the onset of damage mechanism by stress concentration in weakness zones.

  15. Hercynian I-type and S-type granitoids from the Slavonian mountains (southern Pannonian Basin, northern Croatia)

    Science.gov (United States)

    Pamic, J.; Lanphere, M.; Belak, M.

    1996-01-01

    Two genetically different groups of Hercynian granitoids occur in the Slavonian Mountains which are included in the southern Pannonian Basin. I-type granitoids occur in Barrovian-type progressive metamorphic sequences which originated during the Hercynian orogeny from the Late Silurian to Lower Carboniferous magmatic-sedimentary complex. S-type granitoids, enriched in incompatible trace elements, are accompanied by penecontemporaneous migmatites which originated from rocks of the same progressive metamorphic sequences and lower continental crust. I-type granitoids are represented mostly by granodiorite and monzogranite impoverished in incompatible trace elements, with rare diorite and monzodiorite and basic to intermediate rocks. Hercynian age of the crystalline rocks is supported by numerous K-Ar, 40Ar-39Ar and Rb-Sr measurements carried out mostly on monomineralic concentrates. About 20 representative samples of S-type and I-type granites and associated rocks were selected from over 1000 samples and analyzed in detail for major and trace elements, including REE, Sr and O isotopic compositions; microprobe chemical composition of the main rock-forming minerals was determined. Although most major and trace element diagrams do not provide the best genetic discrimination between the Slavonian granitoids, Sr and O isotope composition, REE data and some other data for the S-type granitoids are indicative of their sedimentary and continental crust source, whereas the I-type granitoids were derived by partial melting of the upper mantle with slight crustal contamination.

  16. The molybdenum isotopic compositions of I-, S- and A-type granitic suites

    Science.gov (United States)

    Yang, Jie; Barling, Jane; Siebert, Christopher; Fietzke, Jan; Stephens, Ed; Halliday, Alex N.

    2017-05-01

    This study reports Mo isotopic compositions for fifty-two Palaeozoic granitic rocks with contrasting source affinities (A-, I- and S-type) from the Lachlan Fold Belt (LFB) and the New England Batholith (NEB), both in SE Australia, and three compositionally zoned plutons (Loch Doon, Criffell, and Fleet) located in the Southern Uplands of Scotland. The results show relatively large variations in δ98Mo for igneous rocks ranging from -1.73‰ to 0.59‰ with significant overlaps between different types. No relationships between δ98Mo and δ18O or ASI (Alumina Saturation Index) are observed, indicating that Mo isotopes do not clearly distinguish igneous vs. sedimentary source types. Instead, effects of igneous processes, source mixing, regional geology, as well as hydrothermal activity control the Mo isotope compositions in these granites. It is found that Mo is mainly accommodated in biotite and to a lesser extent in hornblende. Hornblende and Fe3+-rich minerals may preferentially incorporate light isotopes, as reflected by negative correlations between δ98Mo and K/Rb and [Fe2O3]. There is a positive correlation between initial 87Sr/86Sr and δ98Mo in I-type granitic rocks, reflecting the admixing of material from isotopically distinct sources. Granitic rocks from Scotland and Australia display strikingly similar curvilinear trends in δ98Mo vs. initial 87Sr/86Sr despite the differing regional geology. Localized hydrothermal effects can result in low δ98Mo in granite, as seen in three samples from Loch Doon and Criffell which have anomalously light δ98Mo of <-1‰. Based on this study, an estimate of δ98Mo = 0.14 ± 0.07‰ (95% s.e.) for the Phanerozoic upper crust is proposed. This is slightly heavier than basalts indicating an isotopically light lower crust and/or a systematic change to the crust resulting from subduction of isotopically light dehydrated slab and/or pelagic sediment over time.

  17. Effectiveness of granite cleaning procedures in cultural heritage: A review.

    Science.gov (United States)

    Pozo-Antonio, J S; Rivas, T; López, A J; Fiorucci, M P; Ramil, A

    2016-11-15

    Most of the Cultural Heritage built in NW Iberian Peninsula is made of granite which exposition to the environment leads to the formation of deposits and coatings, mainly two types: biological colonization and sulphated black crusts. Nowadays, another form of alteration derives from graffiti paints when these are applied as an act of vandalism. A deep revision needs to be addressed considering the severity of these deterioration forms on granite and the different cleaning effectiveness achieved by cleaning procedures used to remove them. The scientific literature about these topics on granite is scarcer than on sedimentary carbonate stones and marbles, but the importance of the granite in NW Iberian Peninsula Cultural Heritage claims this review centred on biological colonization, sulphated black crusts and graffiti on granite and their effectiveness of the common cleaning procedures. Furthermore, this paper carried out a review of the knowledge about those three alteration forms on granite, as well as bringing together all the major studies in the field of the granite cleaning with traditional procedures (chemical and mechanical) and with the recent developed technique based on the laser ablation. Findings concerning the effectiveness evaluation of these cleaning procedures, considering the coating extraction ability and the damage induced on the granite surface, are described. Finally, some futures research lines are pointed out. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Soil Radon In The Nigerian Younger Granites | Dewu | Nigerian ...

    African Journals Online (AJOL)

    ... not had enough time to attain equilibrium with its daughters. In general, the results suggest that with proper control, soil radon measurements over the Younger Granite can be used for uranium exploration in the region. Keywords: Radon, younger granite, soil uranium, half-lifeand thorium. Nigerian Journal of Physics Vol.

  19. Lithologic features and Uranium possibilities of the granites of ...

    African Journals Online (AJOL)

    Data treatment and interpretation of the result suggest that the fairly enhanced radioactivity in the fine-grained granite, southeast of Pupule, may be related to high background values rather than concentration of uranium minerals in this rock that may justify further more detailed investigation. Keywords: Uranium, Granite ...

  20. 33 CFR 80.525 - Cape Lookout, NC to Cape Fear, NC.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cape Lookout, NC to Cape Fear, NC... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Fifth District § 80.525 Cape Lookout, NC to Cape Fear... southeast side of the Inlet. (g) Except as provided elsewhere in this section from Cape Lookout to Cape Fear...

  1. Total exploitation of an ornamental granite quarry

    Directory of Open Access Journals (Sweden)

    Taboada, J.

    2005-09-01

    Full Text Available In this paper we propose a methodology to estimate the recovery percentage for each of the products which can be obtained from the exploitation of an ornamental granite quarry: block, semiblock, masonry-transverse stone, and the smaller materials that can be used to obtain construction aggregates. This methodology ensures that quarry exploitation is exhaustive, thereby minimising the production of spoils and the consequent negative impact on the environment. The analysis is based on a detailed and exhaustive compilation of discontinuity data from the research fronts, which are then interpreted statistically and projected over the three weakness planes that are a particular feature of ornamental granite deposits. Using this information, and bearing in mind the minimum commercially viable sizes for each kind of granite, the corresponding recovery rates are calculated for each material in each plane. The results are then integrated using spatial techniques, and the result is an evaluation of quarry contents with a view to total exploitation. This methodology was applied to a quarry in the opening phase in order to carry out an a priori assessment of the economic feasibility of the quarry.

    En este trabajo se propone una metodología para estimar el porcentaje de recuperación de cada uno de los productos que se pueden obtener en la explotación de una cantera de granito ornamental: bloque, semibloque, manpostería y per piaños, y material restante destinado a la obtención de áridos. De esta manera se logra un aprovechamiento integral de la cantera, evitándose la generación de estériles y el subsiguiente impacto ambiental producido por éstos. La metodología de análisis se basa en la recopilación detallada y exhaustiva de datos de discontinuidades en los frentes de investigación, que se interpretan estadísticamente y se proyectan sobre los tres planos de debilidad propios del granito ornamental. Con esta información, y las

  2. Granite ascent in convergent orogenic belts: Testing a model

    Science.gov (United States)

    Solar, Gary S.; Pressley, Rachel A.; Brown, Michael; Tucker, Robert D.

    1998-08-01

    The common spatial relationship in convergent orogenic belts between a crustal-scale shear-zone system, high-grade metamorphic rocks, and granites suggests a feedback relation between crustal anatexis and contractional deformation that helps granite extraction and focuses granite ascent. Such a feedback relation has been proposed for ascent of Early Devonian granites in west-central Maine. This interpretation requires that deformation, metamorphism, and plutonism were synchronous. We have determined precise U-Pb zircon and monazite ages that we interpret to record time of crystallization of syntectonic granite in metric to decametric sheets and kilometric plutons, and of schlieric granite within migmatites. Ages are in the range ca. 408 404 Ma, within 1 m.y. at 95% confidence limits. These ages are similar to extant U-Pb monazite ages of ca. 405 399 ± 2 Ma for syntectonic regional metamorphism in the same area. The coincidence between the age of peak metamorphism and crystallization ages of granite shows tectonics, metamorphism, and magmatism were contemporaneous, in support of the feedback model.

  3. Petrogenesis of pegmatites and granites in southwestern Maine

    Energy Technology Data Exchange (ETDEWEB)

    Tomascak, P.B.; Walker, R.J.; Krogstad, E.J. (Univ. of Maryland, College Park, MD (United States). Dept. of Geology)

    1993-03-01

    Granitic pegmatites occurring near the town of Topsham in southwestern Maine are mineralogically diverse, featuring abundant dikes and contain rare earth element minerals as well as one pegmatite that contains Li minerals. The pegmatite series crops out near the Brunswick granite, a texturally diverse granitic pluton, and lies 13 km southeast of the Mississippian age Sebago batholith. Areas intruded by pegmatites that possess such different mineral assemblages are globally rare. The origins of these mixed'' pegmatite series have not been comprehensively investigated. There is no known pattern of regional zonation (mineral/chemical) among Topsham series pegmatites, hence simple fractionation processes are probably not responsible for the compositional variations. The authors are attempting to clarify pegmatite petrogenesis using common Pb isotopic ratios of feldspars and Sm-Nd isotopic data from whole rocks and minerals. Pb isotopic ratios from leached feldspars reflect the Pb ratios of the source from which they were derived. The range of Pb isotopic compositions of alkali feldspars from 7 granitic pegmatites is as follows: [sup 206]Pb/[sup 204]Pb = 18.5-19.1; [sup 207]Pb/[sup 204]Pb = 15.53-15.69; [sup 208]Pb/[sup 204]Pb = 38.3-38.6. The Brunswick granite has K-feldspars with [sup 206]Pb/[sup 204]Pb = 18.40-18.47, [sup 207]/[sup 204]Pb = 15.64-15.66 and [sup 208]Pb/[sup 204]Pb = 38.29-38.39. The Pb isotopic compositions of both pegmatites and granites are significantly more radiogenic than existing data for the Sebago granite and argue against the consanguinity of Topsham pegmatites and the Sebago batholith. These data instead support a genetic link between the pegmatites and the Brunswick granite, which ranges from a fine-grained two-mica granite to a garnet-bearing pegmatitic leucogranite.

  4. 2005 dossier: granite. Tome: phenomenological evolution of the geologic disposal; Dossier 2005: Granite. Tome evolution phenomenologique du stockage geologique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the phenomenological aspects of the geologic disposal of high-level and long-lived radioactive wastes (HLLL) in granite formations. Content: 1 - introduction: ANDRA's research program on disposal in granitic formation; 2 - the granitic environment: geologic history, French granites; 3 - HLLL wastes and disposal design concepts; 4 - identification, characterization and modeling of a granitic site: approach, geologic modeling, hydrologic and hydro-geochemical modeling, geomechanical and thermal modeling, long-term geologic evolution of a site; 5 - phenomenological evolution of a disposal: main aspects of the evolution of a repository with time, disposal infrastructures, B-type wastes disposal area, C-type wastes disposal area; spent fuels disposal area, radionuclides transfer and retention in the granitic environment; 6 - conclusions: available knowledge, methods and tools for the understanding and modeling of the phenomenological evolution of a granitic disposal site. (J.S.)

  5. Petrogenesis of the granitic Donkerhuk batholith in the Damara Belt of Namibia: protracted, syntectonic, short-range, crustal magma transfer

    Science.gov (United States)

    Clemens, J. D.; Buick, I. S.; Kisters, A. F. M.; Frei, D.

    2017-07-01

    The areally extensive (>5000 km2), syn-tectonic, ca. 520 Ma, mainly S-type Donkerhuk batholith was constructed through injection of thousands of mainly sheet-like magma pulses over 20-25 Myr. It intruded schists of the Southern Zone accretionary prism in the Damara Belt of Namibia. Each magma pulse had at least partly crystallised prior to the arrival of the following batch. However, much of the batholith may have remained partially molten for long periods, close to the H2O-saturated granite solidus. The batholith shows extreme variation in chemistry, while having limited mineralogical variation, and seems to be the world's most heterogeneous granitic mass. The Nd model ages of 2 Ga suggest that Eburnean rocks of the former magmatic arc, structurally overlain by the accretionary wedge, are the most probable magma sources. Crustal melting was initiated by mantle heat flux, probably introduced by thermal diffusion rather than magma advection. The granitic magmas were transferred from source to sink, with minimal intermediate storage; the whole process having occurred in the middle crust, resulting in feeble crustal differentiation despite the huge volume of silicic magma generated. Source heterogeneity controlled variation in the magmas and neither mixing nor fractionation was prominent. However, due to the transpressional emplacement régime, local filter pressing formed highly silicic liquids, as well as felsic cumulate rocks. The case of the Donkerhuk batholith demonstrates that emplacement-level tectonics can significantly influence compositional evolution of very large syn-tectonic magma bodies.

  6. Properties of Periwinkle-Granite Concrete | Dahunsi | Journal of Civil ...

    African Journals Online (AJOL)

    Concrete cubes were prepared using 1:0, 1:1, 1:3, 3:1 and 0:1 proportions of periwinkle shells and granite chippings by weight, as coarse aggregate. Compressive strength tests were carried out on the periwinkle-granite concrete cubes. The bulk density of the periwinkle shells was found to be 1353kg/m3 while that for ...

  7. Quality control chart for crushed granite concrete

    Directory of Open Access Journals (Sweden)

    Ewa E. DESMOND

    2016-07-01

    Full Text Available A chart for assessing in-situ grade (strength of concrete, has been developed in this study. Four grades of concrete after the Nigerian General Specification for Roads and bridges (NGSRB-C20, C25, C30 and C35, is studied at different water-cement ratios for medium and high slump range. The concrete mixes are made from crushed granite rock as coarse aggregate with river sand as fine aggregate. Compression test on specimens are conducted at curing age of 1, 3, 7, 14, 21, 28 and 56 days. Results on concrete workability from slump values, and water-cement ratios revealed that specimens with lower water-cement ratio were less workable but had higher strength, compared to mixes with higher water cement ratio. A simple algorithm using nonlinear regression analysis performed on each experimental data set produced Strength-Age (S-A curves which were used to establish a quality control chart. The accuracy of these curves were evaluated by computing average absolute error (AAS, the error of estimate (EoE and the average absolute error of estimate (Abs EoE for each concrete mix. These were done based on the actual average experimental strengths to measure how close the predicted values are to the experimental data set. The absolute average error of estimate (Abs. EoE recorded was less than ±10% tolerance zone for concrete works.

  8. Hydraulic fracturing in granite under geothermal conditions

    Science.gov (United States)

    Solberg, P.; Lockner, D.; Byerlee, J.D.

    1980-01-01

    The experimental hydraulic fracturing of granite under geothermal conditions produces tensile fracture at rapid fluid injection rates and shear fracture at slow injection rates and elevated differential stress levels. A sudden burst of acoustic emission activity accompanies tensile fracture formation whereas the acoustic emission rate increases exponentially prior to shear fracture. Temperature does not significantly affect the failure mechanism, and the experimental results have not demonstrated the occurrence of thermal fracturing. A critical result of these experiments is that fluid injection at intermediate rates and elevated differential stress levels increases permeability by more than an order of magnitude without producing macroscopic fractures, and low-level acoustic emission activity occurs simultaneously near the borehole and propagates outward into the specimen with time. Permeability measurements conducted at atmospheric pressure both before and after these experiments show that increased permeability is produced by permanent structural changes in the rock. Although results of this study have not demonstrated the occurrence of thermal fracturing, they suggest that fluid injection at certain rates in situ may markedly increase local permeability. This could prove critical to increasing the efficiency of heat exchange for geothermal energy extraction from hot dry rock. ?? 1980.

  9. The petrology and geochemistry of alkaline granites from Nigeria

    Science.gov (United States)

    Bowden, P.; Kinnaird, J. A.

    1984-10-01

    The Nigerian younger granites, as well as the petrologically similar but chronologically older northern centres in Aïr and south Niger, constitute the best example of epidosically migrating mid-plate magmatism. The Nigerian anorogenic ring complexes provide a classic example of alkaline granitoid evolution. Each anorogenic centre represents the exposed roots of an eroded volcano. Volcanic assemblages preserved by caldera collapse at some centres confirm that early erupted liquids evolved from olivine basalt through hawaiite, mugearite and trachyte. Although there are volumetrically abundant rhyolitic ignimbrites, there are no volcanic equivalents of biotite granite. However, at the subvolcanic level biotite granites are extensively mineralized with rich deposits of columbite, sphalerite, cassiterite and wolframite. Related peralkaline granites contain enriched concentrations of ore elements but apart from pyrochlore, thorium-rich monazite, and topaz, most potential ores are contained in alkali amphiboles or alkali pyroxene. Fluid interaction in the granite cupolas has caused subsolidus mineral growth and modified original element abundances. In some instances fluid reaction has been so intense that original granite has been locally converted to albite, microclinite, and greisen. These reactions can be monitored by the new mineral assemblages, the major element chemistry, trace elements (e.g., the rare earths) and isotopically by the initial strontium isotopic ratios.

  10. The 'Granite' collegial mission of dialogue. Report; Mission collegiale de concertation Granite. Rapport

    Energy Technology Data Exchange (ETDEWEB)

    Boisson, P.; Huet, Ph.; Mingasson, J

    2000-06-01

    The aim of the 'Granite' collegial mission of dialogue is to inform the French authorities, associations and population about the project of construction of an underground laboratory for the study of the disposal of high level and long-life radioactive wastes in a granitic environment. The aim of the dialogue was not to select a site but to collect the public reactions and advices about such a project. However, such a dialogue has partially failed because of a misunderstanding of the population about the aims of the mission. However, the mission has collected many point of views and questions which are developed in this report. The first and second chapters recall the process of the mission and its progress, while a third chapter stresses on the questions asked by the public and which concern the fear of nuclear wastes and the incompatibility between the disposal of wastes and the socio-economical development of the region concerned. Thanks to the lessons drawn from this experience, the mission has formulated some recommendations (chapter 4) concerning the need for a better information of the population about any topic in relation with the radioactive wastes. Some complementary information is provided in appendixes. (J.S.)

  11. Magmatic Enclaves in Granitic Rocks: Paragons or Parasites?

    Science.gov (United States)

    Clemens, John; Stevens, Gary; Elburg, Marlina

    2017-04-01

    Granitic rocks form the fundamental building blocks of Earth's continents and provide us with a wide range of resources, so their formation is worth trying to understand. Fine-grained, igneous-textured microgranular enclaves of tonalitic to monzogranitic composition (ME) are common in granitic rocks and their origins have been hotly debated, with some workers suggesting that ME are not igneous. These ME have been studied intensively enough that we are now certain that they are of igneous origin - globules of mingled and quenched magma. Although a mantle connection is evident in many cases, their ultimate origin (including where in the lithosphere they originate) is still debated. This contribution explores the systematics of chemical variation in ME and their host granites, with the aim of uncovering any systematics in their behaviour and modelling the processes that have led to the variations that we measure, comparing host-rock series to their respective ME series. As always, the hope is that the study of ME may lead to improved understanding and modelling of the processes that are responsible for the formation of the host granitic magmas. Using variations between the molecular quantities Ti and M (Fe+Mn+Mg), we demonstrate that the petrogenetic processes that operated within a diverse group of S- and I-type granitic host magmas and their ME suites are dissimilar. Variations within the granitic series result from a variety of what might be called 'orderly' processes, resulting in linear or curvilinear trends in chemical variation diagrams. In contrast, processes that affected the ME series commonly resulted in scattered, chaotic variations. Even in cases in which an ME series displays more orderly variation, it can be shown that the hypothesis of simple mixing between a parent enclave magma and its host granitic magma, to produce the overall variations, cannot be supported. ME magmas had vastly smaller volumes compared with their host granitic magmas. Thus, they

  12. Cape Town Open Education Declaration

    OpenAIRE

    Open Society Institute

    2007-01-01

    The Cape Town Open Education Declaration arises from a small but lively meeting convened in Cape Town in September 2007. The aim of this meeting was to accelerate efforts to promote open resources, technology and teaching practices in education. La declaració de Ciutat del Cap per a l'Educació Oberta va sorgir d'una petita però animada reunió a Ciutat del Cap al setembre de 2007. L'objectiu d'aquesta reunió va ser accelerar els esforços per promoure l'obertura en els recursos, la tecnologi...

  13. Petrology of the anorogenic, oxidised Jamon and Musa granites, Amazonian Craton: implications for the genesis of Proterozoic A-type granites

    Science.gov (United States)

    Dall'Agnol, Roberto; Rämö, O. Tapani; de Magalhães, Marilia Sacramento; Macambira, Moacir José Buenano

    1999-03-01

    The 1.88 Ga Jamon and Musa granites are magnetite-bearing anorogenic, A-type granites of Paleoproterozoic age. They intrude the Archaean rocks of the Rio Maria Granite-Greenstone Terrain in the eastern part of the Amazonian Craton in northern Brazil. A suite of biotite±amphibole monzogranite to syenogranite, with associated dacite porphyry (DP) and granite porphyry (GP) dykes, dominates in these subalkaline granites that vary from metaluminous to peraluminous and show high FeO/(FeO+MgO) and K 2O/Na 2O. In spite of their broad geochemical similarities, the Jamon and Musa granites show some significant differences in their REE patterns and in the behaviour of Y. The Jamon granites are related by fractional crystallisation of plagioclase, potassium feldspar, quartz, biotite, magnetite±amphibole±apatite±ilmenite. Geochemical modelling and Nd isotopic data indicate that the Archaean granodiorites, trondhjemites and tonalites of the Rio Maria region are not the source of the Jamon Granite and associated dyke magmas. Archaean quartz diorites, differentiated from the mantle at least 1000 m.y. before the emplacement of the granites, have a composition adequate to generate DP and the hornblende-biotite monzogranite magmas by different degrees of partial melting. A larger extent of amphibole fractionation during the evolution of the Musa pluton can explain some of the observed differences between it and the Jamon pluton. The studied granites crystallised at relatively high fO 2 and are anorogenic magnetite-series granites. In this aspect, as well as concerning geochemical characteristics, they display many affinities with the Proterozoic A-type granites of south-western United States. The Jamon and Musa granites differ from the anorthosite-mangerite-charnockite-rapakivi granite suites of north-eastern Canada and from the reduced rapakivi granites of the Fennoscandian Shield in several aspects, probably because of different magmatic sources.

  14. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2005 spring out-migration at migrant traps on the Snake River and Salmon River. In 2005 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, the age-1 and older fish were distinguishable from wild fish by the occurrence of fin erosion. Age-0 Chinook salmon are more difficult to distinguish between wild and non-adclipped hatchery fish and therefore classified as unknown rearing. The total annual hatchery spring/summer Chinook salmon catch at the Snake River trap was 0.34 times greater in 2005 than in 2004. The wild spring/summer Chinook catch was 0.34 times less than the previous year. Hatchery steelhead trout catch was 0.67 times less than in 2004. Wild steelhead trout catch was 0.72 times less than the previous year. The Snake River trap collected 1,152 age-0 Chinook salmon of unknown rearing. During 2005, the Snake River trap captured 219 hatchery and 44 wild/natural sockeye salmon and 110 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. Trap operations began on March 6 and were terminated on June 3. The trap was out of operation for a total of one day due to heavy debris. FPC requested that the trap be restarted on June 15 through June 22 to collect and PIT tag age-0 Chinook salmon. Hatchery Chinook salmon catch at the Salmon River trap was 1.06 times greater and wild Chinook salmon catch was 1.26 times greater than in 2004. The hatchery steelhead trout collection in 2005 was 1.41 times greater and wild steelhead trout collection was 1.27 times greater than the previous year. Trap operations

  15. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2003 spring out-migration at migrant traps on the Snake River and Salmon River. In 2003 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 2.1 times less in 2003 than in 2002. The wild Chinook catch was 1.1 times less than the previous year. Hatchery steelhead trout catch was 1.7 times less than in 2002. Wild steelhead trout catch was 2.1 times less than the previous year. The Snake River trap collected 579 age-0 Chinook salmon of unknown rearing. During 2003, the Snake River trap captured five hatchery and 13 wild/natural sockeye salmon and 36 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant differences in catch between 2003 and the previous year were due mainly to low flows during much of the trapping season and then very high flows at the end of the season, which terminated the trapping season 12 days earlier than in 2002. Trap operations began on March 9 and were terminated on May 27. The trap was out of operation for a total of zero days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 16.8% less and wild Chinook salmon catch was 1.7 times greater than in 2002. The hatchery steelhead trout collection in 2003 was 5.6% less than in 2002. Wild steelhead trout collection was 19.2% less than the previous year. Trap operations began on March 9 and were terminated on May 24 due to high

  16. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 2002 spring out-migration at migrant traps on the Snake River and Salmon River. In 2002 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 11.4 times greater in 2002 than in 2001. The wild Chinook catch was 15.5 times greater than the previous year. Hatchery steelhead trout catch was 2.9 times greater than in 2001. Wild steelhead trout catch was 2.8 times greater than the previous year. The Snake River trap collected 3,996 age-0 Chinook salmon of unknown rearing. During 2002, the Snake River trap captured 69 hatchery and 235 wild/natural sockeye salmon and 114 hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant increase in catch in 2002 was due to a 3.1 fold increase in hatchery Chinook production and a more normal spring runoff. Trap operations began on March 10 and were terminated on June 7. The trap was out of operation for a total of four days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 4.2 times greater and wild Chinook salmon catch was 2.4 times greater than in 2001. The hatchery steelhead trout collection in 2002 was 81% of the 2001 numbers. Wild steelhead trout collection in 2002 was 81% of the previous year's catch. Trap operations began on March 10 and were terminated on May 29 due to high flows. The trap was out of operation for four days due to high flow or debris. The

  17. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2004 spring out-migration at migrant traps on the Snake River and Salmon River. In 2004 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 1.1 times greater in 2004 than in 2003. The wild Chinook catch was 1.1 times greater than the previous year. Hatchery steelhead trout catch was 1.2 times greater than in 2003. Wild steelhead trout catch was 1.6 times greater than the previous year. The Snake River trap collected 978 age-0 Chinook salmon of unknown rearing. During 2004, the Snake River trap captured 23 hatchery and 18 wild/natural sockeye salmon and 60 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. Trap operations began on March 7 and were terminated on June 4. The trap was out of operation for a total of zero days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 10.8% less and wild Chinook salmon catch was 19.0% less than in 2003. The hatchery steelhead trout collection in 2004 was 20.0% less and wild steelhead trout collection was 22.3% less than the previous year. Trap operations began on March 7 and were terminated on May 28 due to high flows. There were two days when the trap was taken out of service because wild Chinook catch was very low, hatchery Chinook catch was very high, and the weekly quota of PIT tagged hatchery Chinook had been met. Travel time (d) and migration rate (km

  18. Geochronological and geochemical constraints on the petrogenesis of the early Paleoproterozoic potassic granite in the Lushan area, southern margin of the North China Craton

    Science.gov (United States)

    Zhou, Yanyan; Zhai, Mingguo; Zhao, Taiping; Lan, Zhongwu; Sun, Qianying

    2014-11-01

    We conducted a geochronological and geochemical study on the Paleoproterozoic potassic granites in the Lushan area, southern margin of the North China Craton (NCC) to understand the tectonic regime of the NCC at 2.2-2.1 Ga. This rock suite formed at 2194 ± 29 Ma. The rocks are rich in SiO2 (76.10-77.73 wt.%), and K2O (5.94-6.90 wt.%) with high K2O + Na2O contents from 7.56 wt.% to 8.48 wt.%, but poor in CaO (0.10-0.28 wt.%), P2O5 (0.02-0.05 wt.%) and MgO (0.01-0.30 wt.%, Mg# = 1.08-27.3), indicating they experienced fractional crystallization. Major element compositions suggest the potassic granites share an affinity with high K calc-alkaline granite. Even though the Lushan potassic granitic rocks have high A/CNK ratios (1.11-1.25), which can reach peraluminous feature, the very low P2O5 contents and negative correlation of P2O5 and SiO2 ruling out they are S-type granites. Different from peralkaline A-type granites, the Lushan potassic granites have variable Zr concentrations (160-344 ppm, 226 ppm on average) and 10,000 Ga/Al ratios (1.76-3.00), together with high zircon saturation temperatures (TZr = 826-885 °C), indicating they are fractionated aluminous A-type granites. Enriched LREE ((La/Yb)N = 9.72-81.8), negative Eu anomalies, and low Sr/Y with no correlations in Sr/Y and Sr/Zr versus CaO suggest the possible presence of Ca-rich plagioclase and absence of garnet in the residual. Magmatic zircon grains have variable εHf(t) values (-2.4 to +7.3) with zircon two-stage Hf model ages (TDMC) varying from 2848 Ma to 2306 Ma (mostly around ca. 2.5 Ga), and are plotted in the evolution line of crustal felsic rock. We propose that the rocks mainly formed by partial melting of ca. 2.50 Ga tonalitic-granodioritic crust as a result of upwelling mantle-derived magmas which provided thermal flux and source materials in an intra-continent rifting. The ca. 2.2 Ga magmatism suggests that intra-continental rifting occurred at 2.35-1.97 Ga at least in the southern margin of

  19. Design analysis of machine tool structure with artificial granite material

    Directory of Open Access Journals (Sweden)

    Tsung-Chia Chen

    2016-06-01

    Full Text Available Artificial granite material has been used for construction of the high-precision machine due to superior damping ability. However, its lower material stiffness also lessens the application in fabrication of the machine tool. The purpose of this study was therefore aimed to verify the structure performance of the machine tool reformed with artificial granite material, instead of the casting iron. To gain insight into the optimized configuration of the vertical columns and spindle head stock, the static and dynamic characteristics of the machine models with cast iron and granite composites were predicted for comparison. With this, evaluations of the machine with different design were made to examine the experimental measurements on the prototype machine. According to the simulation results and experimental measurements, the static stiffness of the machine tool reformed with granite material is comparable to the original casting machine, differed by 8% approximately. However, granite machine shows superior dynamic stiffness, about 0.5–1.3 times of the conventional casting machine. This study verifies the feasibility and effectiveness in fabrication of the machine tool with the artificial composite material and provides the improvements for further fabrications.

  20. 1992 Cape Mendocino, USA Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On April 25, 1992 at 11:06 am local time (April 25 at 18:06 GMT), a magnitude 7.1 earthquake occurred in the Cape Mendocino area. Two additional earthquakes,...

  1. GRANITE CUTTING WASTE: TECHNOLOGICAL INNOVATION FOR THE FINAL DESTINATION

    Directory of Open Access Journals (Sweden)

    Joner Oliveira Alves

    2015-06-01

    Full Text Available The granite processing market is one of the most promising business areas of the mineral sector, with an average growth of the world production of about 6% per year. The granite extraction generates residues in the form of powder rock of 20-25 wt.% of the total benefited. The granite dust must be carefully managed since it can cause siltation of rivers and human health risks. This paper presents two routes for the final destination of this waste: the vitrification process aiming the production of fibers for thermo-acoustic insulation, and the magnetic separation in order to recover the steel grit. Results showed that the forms of treatments presented are economically and ecologically viable since they represent a cost reduction in the waste disposal, and also provide the production of new materials with commercial value.

  2. Analysis of Shield Construction in Spherical Weathered Granite Development Area

    Science.gov (United States)

    Cao, Quan; Li, Peigang; Gong, Shuhua

    2018-01-01

    The distribution of spherical weathered bodies (commonly known as "boulder") in the granite development area directly affects the shield construction of urban rail transit engineering. This paper is based on the case of shield construction of granite globular development area in Southern China area, the parameter control in shield machine selection and shield advancing during the shield tunneling in this special geological environment is analyzed. And it is suggested that shield machine should be selected for shield construction of granite spherical weathered zone. Driving speed, cutter torque, shield machine thrust, the amount of penetration and the speed of the cutter head of shield machine should be controlled when driving the boulder formation, in order to achieve smooth excavation and reduce the disturbance to the formation.

  3. Morphological characteristics of Cape sugarbirds ( Promerops cafer ...

    African Journals Online (AJOL)

    Cape sugarbirds (Promerops cafer) are the largest nectarivores in the Western Cape and feed almost exclusively on protea nectar and associated arthropods. Helderberg Nature Reserve, Western Cape, South Africa, has a large diversity of Protea and supports breeding sugarbirds. As part of a larger study, we captured ...

  4. 76 FR 38302 - Safety Zone; Cape Charles Fireworks, Cape Charles Harbor, Cape Charles, VA

    Science.gov (United States)

    2011-06-30

    ... navigable waters of Cape Charles City Harbor centered on position 37 15'46.5'' N/076 01'30'' W (NAD 1983... of materials, performance, design, or operation; test methods; sampling procedures; and related... the human environment. This rule is categorically excluded, under figure 2-1, paragraph (34)(g), of...

  5. Oxidized, magnetite-series, rapakivi-type granites of Carajás, Brazil: Implications for classification and petrogenesis of A-type granites

    Science.gov (United States)

    Dall'Agnol, Roberto; de Oliveira, Davis Carvalho

    2007-02-01

    The varying geochemical and petrogenetic nature of A-type granites is a controversial issue. The oxidized, magnetite-series A-type granites, defined by Anderson and Bender [Anderson, J.L., Bender, E.E., 1989. Nature and origin of Proterozoic A-type granitic magmatism in the southwestern United States of America. Lithos 23, 19-52.], are the most problematic as they do not strictly follow the original definition of A-type granites, and approach calc-alkaline and I-type granites in some aspects. The oxidized Jamon suite A-type granites of the Carajás province of the Amazonian craton are compared with the magnetite-series granites of Laurentia, and other representative A-type granites, including Finnish rapakivi and Lachlan Fold Belt A-type granites, as well as with calc-alkaline, I-type orogenic granites. The geochemistry and petrogenesis of different groups of A-types granites are discussed with an emphasis on oxidized A-type granites in order to define their geochemical signatures and to clarify the processes involved in their petrogenesis. Oxidized A-type granites are clearly distinguished from calc-alkaline Cordilleran granites not only regarding trace element composition, as previously demonstrated, but also in their major element geochemistry. Oxidized A-type granites have high whole-rock FeO t/(FeO t + MgO), TiO 2/MgO, and K 2O/Na 2O and low Al 2O 3 and CaO compared to calc-alkaline granites. The contrast of Al 2O 3 contents in these two granite groups is remarkable. The CaO/(FeO t + MgO + TiO 2) vs. CaO + Al 2O 3 and CaO/(FeO t + MgO + TiO 2) vs. Al 2O 3 diagrams are proposed to distinguish A-type and calc-alkaline granites. Whole-rock FeO t/(FeO t + MgO) and the FeO t/(FeO t + MgO) vs. Al 2O 3 and FeO t/(FeO t + MgO) vs. Al 2O 3/(K 2O/Na 2O) diagrams are suggested for discrimination of oxidized and reduced A-type granites. Experimental data indicate that, besides pressure, the nature of A-type granites is dependent of ƒO 2 conditions and the water content

  6. 33 CFR 165.530 - Safety Zone: Cape Fear and Northeast Cape Fear Rivers, NC.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone: Cape Fear and Northeast Cape Fear Rivers, NC. 165.530 Section 165.530 Navigation and Navigable Waters COAST GUARD... § 165.530 Safety Zone: Cape Fear and Northeast Cape Fear Rivers, NC. (a) Location. The following area is...

  7. The Swedish Bohus granite - a stone with a fascinating history

    Science.gov (United States)

    Schouenborg, Björn; Eliasson, Thomas

    2015-04-01

    One of the most well-known and well spread Swedish stone types used as building stones is the Bonus granite. It outcrops in an area north of Gothenburgh (SW Sweden), along the coastline, approximately 35 km wide and 85 km long. The granite continues into Norway as the Iddefjord granite. The Bohus granite is one of Sweden's youngest granites. Isotopic dating shows that the magma cooled at about 920 M years ago and thus marking the end of the Sveconorwegian orogoney. It is a composite granite massif area with several granitic intrusions but with rather homogeneous mineralogy. However, colour and texture varies quite a lot and the colour ranges from red to reddish grey although some pure grey varieties occur sparsely. The grain size ranges from medium grained to coarse grained and even with some porphyric parts. Quarrying in an industrial scale started 1842. The merchant A C Kullgren opened the first quarry and produced stones for the construction of the 86 km long Trollhättan channel connecting lake Vänern and the Atlantic ocean in the SW Sweden The stone was used for constructing harbors and wharves along the channel. Several quarries opened in the late 1800 around 1870 - 1890 and the export increased steadily with deliveries to Germany, Denmark, Holland, England and even to South America. The stone industries in Bohuslän (Bohus county), at its peak in 1929, engaged around 7 000 employees. During the depression in 1930 almost all of them became unemployed. However, as a curiosity, production and export continued to Germany for construction of Germania, the future World capital city ("Welthauptstadt Germania"), planned by Adolf Hitler and Albert Speer. About 500 stone workers were kept employed for this project during the late thirties. Today several varieties are still produced: Evja/Ävja, Tossene, Brastad, Näsinge, Broberg, Nolby, Allemarken and Skarstad. However, the number of stone workers is far from that of the early 1900. The Swedish production is mainly

  8. Peralkaline and peraluminous granites and related mineral deposits of the Arabian Shield, Kingdom of Saudi Arabia

    Science.gov (United States)

    Elliott, James E.

    1983-01-01

    In the Precambrian Arabian Shield, granitoid plutonic rocks are widespread and range in age from 800 to 550 Ma old; but the mineral-resource potential associated with these plutonic rocks is restricted mainly to the younger, postorogenic granites. Two granite types of current economic interest are zirconium- niobium-enriched per alkaline granites and tin-tungsten-enriched peraluminous granites. Both types are highly evolved, are enriched in lithium, rubidium, and fluorine, and have distinctive mineralogy, textures, and chemistry. The zirconium-niobium-enriched granites are related to medium- to large-sized plutons and complexes of peralkaline granite, and the tin-tungsten-enriched granites are related to medium-sized plutons of biotite or biotite-muscovite granite.

  9. Genesis of a zoned granite stock, Seward Peninsula, Alaska

    Science.gov (United States)

    Hudson, Travis

    1977-01-01

    A composite epizonal stock of biotite granite has intruded a diverse assemblage of metamorphic rocks in the Serpentine Hot Springs area of north-central Seward Peninsula, Alaska. The metamorphic rocks include amphibolite-facies orthogneiss and paragneiss, greenschist-facies fine-grained siliceous and graphitic metasediments, and a variety of carbonate rocks. Lithologic units within the metamorphic terrane trend generally north-northeast and dip moderately toward the southeast. Thrust faults locally juxtapose lithologic units in the metamorphic assemblage, and normal faults displace both the metamorphic rocks and some parts of the granite stock. The gneisses and graphitic metasediments are believed to be late Precambrian in age, but the carbonate rocks are in part Paleozoic. Dating by the potassium-argon method indicates that the granite stock is Late Cretaceous. The stock has sharp discordant contacts, beyond which is a well-developed thermal aureole with rocks of hornblende hornfels facies. The average mode of the granite is 29 percent plagioclase, 31 percent quartz, 36 percent K-feldspar, and 4 percent biotite. Accessory minerals include apatite, magnetite, sphene, allanite, and zircon. Late-stage or deuteric minerals include muscovite, fluorite, tourmaline, quartz, and albite. The stock is a zoned complex containing rocks with several textural facies that are present in four partly concentric zones. Zone 1 is a discontinuous border unit, containing fine- to coarse-grained biotite granite, that grades inward into zone 2. Zone 2 consists of porphyritic biotite granite with oriented phenocrysts of pinkish-gray microcline in a coarse-grained equigranular groundmass of plagioclase, quartz, and biotite. It is in sharp, concordant to discordant contact with rocks of zone 3. Zone 3 consists of seriate-textured biotite granite that has been intruded by bodies of porphyritic biotite granite containing phenocrysts of plagioclase, K-feldspar, quartz, and biotite in an

  10. From granite to highly evolved pegmatite: A case study of the Pinilla de Fermoselle granite-pegmatite system (Zamora, Spain)

    Science.gov (United States)

    Roda-Robles, E.; Pesquera, A.; Gil-Crespo, P.; Torres-Ruiz, J.

    2012-11-01

    The Pinilla de Fermoselle pegmatite is a cap-like body with an asymmetrical vertical zoning, from a granitic facies at the bottom to the upper contact with the metamorphic country-rocks. The granite grades imperceptibly into the pegmatite, which includes three main zones with different degrees of enrichment in Li + F + B (± P, Rb, Cs, Be, Sn). The essential minerals are quartz, feldspar, Al-micas from the muscovite-lepidolite series, Fe-micas (biotite and zinnwaldite), tourmaline (schorl-elbaite-rossmanite) and Fe-Mn phosphates. Apatite, beryl, cassiterite and cookeite are the most significant accessory minerals. The trace elements Li, Be and Sr show similar trends in feldspar, micas and tourmaline, with an increase in the Li and Be contents and a decrease in Sr from the granite to the most evolved pegmatitic zone. Similar trends are shown by Rb, Cs and Ba for micas and K-feldspar, Rb and Cs increasing gradually from the granite to most evolved pegmatitic zones, simultaneously to the decrease of Ba. In tourmaline Nb and Ta contents increase upwards whereas Zn contents decrease in the same way. The Mn contents increase until intermediate degrees of evolution, and decrease again in the pinkish elbaite. Combined field, petrographic and geochemical data are consistent with a fractional crystallization model from a granitic melt, with a clear petrogenetic relationship between the underlying peraluminous granite and the pegmatite body. K-feldspar and, particularly, micas and tourmaline appear as good geochemical monitors using trace elements such as Li, Rb, Be, Sr and Ba, which offer intriguing insights into the petrogenesis of pegmatites.

  11. A Cape for Staying Connected

    Science.gov (United States)

    Goldman, Jay P.

    2005-01-01

    Some think a good superintendent these days shares a lot in common with a superhero. Larry Hill is one superintendent who really does don a cape. It is a flowing black one, complemented by a sparkly white bow tie and red top hat. And better yet, he wears it on his job as the top administrator of the North Iowa Community Schools in Buffalo Center,…

  12. CAPE TOWN'S TIME-GUNS

    African Journals Online (AJOL)

    South African Astronomical Observatory) along a Post Office line to Lion Battery6 On 26 August. 1865 the time signals were given at 'the instant of one o'clock. '7. On 14 May 1918, the Mayor of Cape Town,. Councillor (late Sir Harry) Hands instituted the mid-day pause.s The boom of the noon gun be- came the signal for a ...

  13. MISR Looks at Cape Cod

    Science.gov (United States)

    2000-01-01

    Each year in late November the United States observes the Thanksgiving holiday, commemorating the harvest festival celebrated by the Plymouth colonists and the Native Americans who helped them survive the devastating winter of 1620. Plymouth, Massachusetts, where the Mayflower Pilgrims landed, is located on the west side of Cape Cod Bay, shown in this MISR vertical-viewing (nadir) camera image. This nearly cloud-free picture was acquired on April 13, 2000 during Terra orbit 1708.South of the distinctively-shaped Cape Cod are Nantucket Island and Martha's Vineyard. Further west is Block Island, south of Narragansett Bay, Rhode Island. Montauk Point on the eastern tip of Long Island, New York, is visible at the lower left. On the mainland, Providence and Boston appear as gray patches. Jutting out from the Massachusetts coastline, northeast of Boston, is Cape Ann, location of the city of Gloucester, which was settled soon after the Pilgrim's arrival in Plymouth. Gloucester is the oldest fishing port in the eastern United States.MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  14. predicting the compressive strength of concretes made with granite

    African Journals Online (AJOL)

    2013-03-01

    Mar 1, 2013 ... to civil engineers and construction professionals, and would help in economically determining the strength, as well as economical selection of appropriate mix of construction materials, a prelude to building strong and cheap buildings and structures. Keywords: artificial neural network, concrete, granite, ...

  15. lateritic weathering of granite-gneiss in obudu plateau, south ...

    African Journals Online (AJOL)

    DJFLEX

    This paper reports the chemical, mineralogical and textural changes involved in the lateritization of granite-gneiss in. Obudu plateau and establishes that the susceptibility of constituent minerals to lateritic weathering is in the sequence; feldspar, Hornblende, Biotite, Quartz. Most of the chemical constituents of the basement ...

  16. Evolutionary trend of the Jarawa younger granites ring complex, Jos ...

    African Journals Online (AJOL)

    Results from geochemical studies supports the above findings, indicating high CaO and MgO content that decreases from the Hornblende Porphyry through the Hornblende Biotites to the coarsed grained Biotite Granites and the Microgranites respectively. Also, all the lithologic units exhibited high alkali content (Na2O + ...

  17. Fracture systems in the younger granite rocks around fobur, northern ...

    African Journals Online (AJOL)

    Outcrop-scale fractures and associated veins found in the Younger Granite rocks around Fobur, Northern Nigeria were studied in relation to similar structures in their host rocks (Migmatites-gneisses -quartzite complex). Fractures and veins attitude (strike and dip) data were collected across the study area and subjected to ...

  18. Aggregate impact testing of selected granite samples from sites in ...

    African Journals Online (AJOL)

    The Aggregate Impact Testing machine was used to measure the resistance to fa ilure of Rocks from five (5) selected granite quarries to a suddenly applied force using S ingapore standard. The results obtained show that brittleness (S20) value of the rocks were between 2 - 10. These values are less than the stated ...

  19. Geochemical study of volcanic and associated granitic rocks from ...

    Indian Academy of Sciences (India)

    Geochemical studies and modelling show that both volcanic and granitic magmas from the western part of the Johor National Park, Endau Rompin are different and probably have different sources. The geo- chemical plot suggests that both dacite/rhyolite and andesite probably have a common origin as in many.

  20. An investigation on surface roughness of granite machined by ...

    Indian Academy of Sciences (India)

    Administrator

    submerged waterjet with a free jet operating in air for red granite cutting in terms of cut depth. Matsuki et al (1988) expanded the comparison considering the influence of the impinging angle and standoff distance on the cut depth in rock. Further, parameters such as rock temperature, physical properties of rock and process ...

  1. Water–rock interaction on the development of granite gneissic ...

    Indian Academy of Sciences (India)

    profiles due to their strong dependency on lithology, and corresponding climate and tectonic interaction. Contrasting elemental ... Chemical alteration; granite gneisses; elemental mobility; climate–tectonic interaction; Lesser Himalaya. J. Earth Syst. Sci. .... and gradual change in colour can be observed dur- ing weathering ...

  2. Preface: A short geophysical history of Westerly granite

    Science.gov (United States)

    Scholz, C. H.

    A number of rocks have achieved a kind of fame in geophysical circles because of their frequent use in experimental studies. The names Carrera marble, which has attained a far larger fame in its use for Italian sculpture and facades, Yule marble, and Solenhofen limestone come immediately to mind as experimentalists' rocks. None, however, can match the longevity and shear body of study devoted to them as that of the granite from Westerly, Rhode Island. It is because of the great attention that has been played upon this rock and because of the considerable difficulty one encounters in obtaining a sample of it (it has not been commercially quarried in over 25 years), that Westerly granite has achieved a sort of cult status among experimental geophysicists. It is ironic that many who use the well-worn quip "geophysicists think that the crust is made of Westerly granite" are probably unaware that Westerly granite was once designated by the U.S. Geological Survey and the Carnegie Institution as `G-1', the type rock of the continental crust [Fairbairn et al., 1951].

  3. Effects of Weathering on Mechanical Properties of Granite Gneiss ...

    African Journals Online (AJOL)

    This paper describes the geotechnical characteristics of granite gneiss and dolerite from Oban and Obuduregions in South-eastern Nigeria. The suitability of these rocks for civil construction purposes and the effects of weathering on their mechanical properties are examined. The results indicate that compressive strength ...

  4. Geochemistry and petrogenesis of Proterozoic granitic rocks from ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 5. Geochemistry and petrogenesis of Proterozoic granitic rocks from northern margin of the Chotanagpur Gneissic Complex (CGC). Bhupendra S Yadav Nishchal Wanjari Talat Ahmad Rajesh Chaturvedi. Volume 125 Issue 5 July 2016 pp 1041-1060 ...

  5. Fourier-transform Infrared Characterization of Kaolin, Granite ...

    African Journals Online (AJOL)

    Fourier-transform Infrared Characterization of Kaolin, Granite, Bentonite and Barite. ... Diazonium salts at the peak region frequency of 3200-3100cm-1, organic substance at peak region of 2900-2700cm-1, by comparing the spectra obtained with those ... Keywords: characterization; clays; infrared; minerals; spectroscopy ...

  6. Erosion over time on severely disturbed granitic soils: a model

    Science.gov (United States)

    W. F. Megahan

    1974-01-01

    A negative exponential equation containing three parameters was derived to describe time trends in surface erosion on severely disturbed soils. Data from four different studies of surface erosion on roads constructed from the granitic materials found in the Idaho Batholith were used to develop equation parameters. The evidence suggests that surface "armoring...

  7. Monte Carlo simulations for generic granite repository studies

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Shaoping [Los Alamos National Laboratory; Lee, Joon H [SNL; Wang, Yifeng [SNL

    2010-12-08

    In a collaborative study between Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL) for the DOE-NE Office of Fuel Cycle Technologies Used Fuel Disposition (UFD) Campaign project, we have conducted preliminary system-level analyses to support the development of a long-term strategy for geologic disposal of high-level radioactive waste. A general modeling framework consisting of a near- and a far-field submodel for a granite GDSE was developed. A representative far-field transport model for a generic granite repository was merged with an integrated systems (GoldSim) near-field model. Integrated Monte Carlo model runs with the combined near- and farfield transport models were performed, and the parameter sensitivities were evaluated for the combined system. In addition, a sub-set of radionuclides that are potentially important to repository performance were identified and evaluated for a series of model runs. The analyses were conducted with different waste inventory scenarios. Analyses were also conducted for different repository radionuelide release scenarios. While the results to date are for a generic granite repository, the work establishes the method to be used in the future to provide guidance on the development of strategy for long-term disposal of high-level radioactive waste in a granite repository.

  8. Geochemical study of volcanic and associated granitic rocks from ...

    Indian Academy of Sciences (India)

    Geochemical studies and modelling show that both volcanic and granitic magmas from the western part of the Johor National Park, Endau Rompin are different and probably have different sources. The geochemical plot suggests that both dacite/rhyolite and andesite probably have a common origin as in many of the ...

  9. Etude de la diagraphie neutron du granite de Beauvoir. Effet neutron des altérations et de la matrice du granite. Calibration granite. Porosité totale à l'eau et porosité neutron Analysis of the Beauvoir Granite Neutron Log. Neutron Effect of Alterations and of the Granite Matrix. Granite Calibration. Total Water Porosity and Neutron Porosity

    Directory of Open Access Journals (Sweden)

    Galle C.

    2006-11-01

    Full Text Available Cet article rend compte des travaux effectués sur la porosité du granite de Beauvoir (Sondage GPF 1 d'Echassières, Massif Central français. L'objectif de notre étude est de pouvoir obtenir des valeurs représentatives de la saturation en eau (porosité totale à l'eau n du granite de Beauvoir à partir des mesures de porosité neutron PorositéN (diagraphie neutron BRGM sans avoir recours aux mesures sur carottes. Notre démarche est expérimentale et nous avons tenté d'approfondir certains problèmes liés à l'utilisation de la diagraphie neutron dans une roche granitique. Deux facteurs principaux conditionnent la réponse neutron : la concentration en hydrogène de la formation (eau libre et eau de constitution de certains minéraux et la présence d'éléments absorbeurs à forte section de capture comme le gadolinium, le cadmium, le bore, . . . et dans le cas du granite de Beauvoir, le lithium. A partir des mesures de porosité totale à l'eau n sur carottes, des essais de pertes au feu sur poudre qui nous permettent de déterminer la porosité neutron liée à l'eau de constitution PorositéN(OH- et des analyses chimiques avec lesquelles nous évaluons la porosité neutron thermique PorositéN(ox (Programme SNUPAR, Schlumberger liée à la capture neutronique, nous reconstituons la porosité neutron totale PorositéNR du granite de Beauvoir. Pour 7 échantillons caractéristiques du granite de Beauvoir, nous réalisons grâce à ces résultats une nouvelle calibration du taux de comptage neutron initial corrigé du gradient thermique et de l'effet de trou. Grâce à cette opération, il est possible de déterminer, pour les échantillons traités, la porosité neutron du granite avec une calibration granite (PorositéNg et non calcaire (PorositéNc. La connaissance de l'effet neutron de la matrice nous permet enfin d'évaluer la teneur en eau du granite (porosité totale à l'eau et de comparer celle-ci avec la porosité mesurée sur

  10. Fracture controls on valley persistence: the Cairngorm Granite pluton, Scotland

    Science.gov (United States)

    Hall, A. M.; Gillespie, M. R.

    2017-09-01

    Valleys are remarkably persistent features in many different tectonic settings, but the reasons for this persistence are rarely explored. Here, we examine the structural controls on valleys in the Cairngorms Mountains, Scotland, part of the passive margin of the eastern North Atlantic. We consider valleys at three scales: straths, glens and headwater valleys. The structural controls on valleys in and around the Cairngorm Granite pluton were examined on satellite and aerial photographs and by field survey. Topographic lineaments, including valleys, show no consistent orientation with joint sets or with sheets of microgranite and pegmatitic granite. In this granite landscape, jointing is not a first-order control on valley development. Instead, glens and headwater valleys align closely to quartz veins and linear alteration zones (LAZs). LAZs are zones of weakness in the granite pluton in which late-stage hydrothermal alteration and hydro-fracturing have greatly reduced rock mass strength and increased permeability. LAZs, which can be kilometres long and >700 m deep, are the dominant controls on the orientation of valleys in the Cairngorms. LAZs formed in the roof zone of the granite intrusion. Although the Cairngorm pluton was unroofed soon after emplacement, the presence of Old Red Sandstone (ORS) outliers in the terrain to the north and east indicates that the lower relief of the sub-ORS basement surface has been lowered by 1 km of vertical erosion and for 400 Myr. This valley persistence is a combined product of regionally low rates of basement exhumation and of the existence of LAZs in the Cairngorm pluton and sub-parallel Caledonide fractures in the surrounding terrain with depths that exceed 1 km.

  11. Emplacement of ellipsoid-shaped (diapiric?) granite: Structural and gravimetric analysis of the Oulmès granite (Variscan Meseta, Morocco)

    Science.gov (United States)

    Tahiri, Abdelfatah; Simancas, J. Fernando; Azor, Antonio; Galindo-Zaldívar, Jesús; González Lodeiro, Francisco; El Hadi, Hassan; Martínez Poyatos, David; Ruiz-Constán, Ana

    2007-08-01

    The Oulmès granite is a NE-SW elongated stock intruded in Ordovician metasedimentary rocks which crop out at the core of a regional anticlinorium of the Moroccan Variscan Meseta. The stock, dated at around 300 Ma, is made up of peraluminous two-mica granite, with subordinate amounts of muscovite leucogranite. Mineral composition and textural features of both the granite and the thermal aureole enable us to constrain the P-T conditions during magma intrusion in ≈250-300 MPa and ≈600 °C at the contact between the granite and its host rock. Emplacement of the Oulmès granite postdates the main regional structures and is coeval with the late stages of Variscan compression. Prior to granite intrusion, the host rocks were affected by a main deformation phase responsible for the development of a penetrative slaty cleavage and regional-scale folds. Granite emplacement gave way to a 2 km-thick strain aureole, which includes both the uppermost part of the stock and the surrounding host rocks. The strain aureole is characterized by a gently-dipping planar-linear fabric with a generally weak N-S oriented stretching lineation. In the granite, the fabric of the strain aureole consists of a solid-state, locally mylonitic, foliation. In the host rocks, a secondary foliation develops which crenulates the older regional foliation. Magmatic structures, mainly consisting of steeply dipping N-S oriented magmatic foliation, are preserved in the central part of the pluton. The 3D shape of the granite has been modelled from gravity data and, together with the observed magmatic flow along subvertical planes and the strain recorded in the aureole, leads us to envisage a diapiric-dominated mechanism for the emplacement of the Oulmès granite. Drawing on the petrogenesis of peraluminous granites, the diapiric ascent of the granite probably has not exceeded 10 km.

  12. Zarzalejo granite (Spain). A nomination for 'Global Heritage Stone Resource'

    Science.gov (United States)

    Freire Lista, David Martin; Fort, Rafael; José Varas-Muriel, María

    2015-04-01

    Zarzalejo granite is quarried in the Sierra de Guadarrama (Spanish Central System) foothills, in and around Zarzalejo village, in the province of Madrid, Spain. It is an inequigranular monzogranite medium-to-coarse grained, with a slight porphyritic texture (feldspar phenocrysts) and mafic micro-grained enclaves. In this abstract the candidacy of Zarzalejo granite as a "Global Heritage Resource Stone" (GHSR) is presented. This stone ideally fits the newly proposed designation as it has been used in many heritage buildings and its good petrophysical properties and durability have allowed well preserved constructions such as a Roman road, San Pedro Church in Zarzalejo (1492), Descalzas Reales Monastery in Madrid (1559-1564) and the San Lorenzo del Escorial Royal Monastery (1563-1584), to be declared a World Heritage Site by UNESCO. This level of construction has been a landmark in the extraction and proliferation of historic quarries created due to the high demand that such colossal monuments and buildings with granite, have required for their construction. In the mid-20th century, More, Zarzalejo granite has also been used in restoration works including the Royal Palace and the Reina Sofía Museum (2001-2005), both buildings in Madrid, Spain. Extraction of granite ashlars from tors has been a very frequent activity in the Zarzalejo neighbourhood until mid-twentieth century. So there is also a need to preserve these historic quarries. This type of stone has created a landscape that has been preserved as an open-air museum today where you can see the marks left in the granite due to historic quarry operations. The granite industry has been one of the main pillars of the Zarzalejo regional economy. For centuries, the local community have been engaged in quarrying and have created a cultural landscape based on its building stone. A quarryman monument has been erected in Zarzalejo in honor of this traditional craft as well as an architecture museum at San Lorenzo del

  13. Experimental analysis on physical and mechanical properties of thermal shock damage of granite

    Directory of Open Access Journals (Sweden)

    He Xiao

    2017-01-01

    Full Text Available The purpose of this study was to explore the changes of mechanical and physical properties of granite under different thermal loading effects. Uniaxial compression experiments studying the rules of the influence of temperature load on mechanical properties of granite were carried out. After high-temperature heating at above 600 °C, granite tended to have stronger ductility and plasticity as well as declined peak stress and compressive strength. Thermogravimetry - differential scanning calorimetry (TG-DSC analysis results showed that, thermal load at different temperatures induced reactions such as water loss, oxidation and crystallization in the microstructure of granite, which led to physical changes of granite. Hence it is concluded that, heating can significantly weaken the mechanical performance of granite, which provides an important support for the optimization of heating assisted processing of granite. It also reveals that, heating assisted cutting technique can effectively lower energy consumption and improve processing efficiency.

  14. Alteration of granite stone used in building construction

    Directory of Open Access Journals (Sweden)

    Esbert Alemany, R. M.ª

    2007-12-01

    Full Text Available The article contains a synthesis of the different factors involved in the alteration of granite ashlars or cladding used in building construction. Emphasis is placed on the – primarily fissure-like – anisotropies often present in granite, which are usually related to the structural conditions of the quarry where it is mined. Such anisotropies condition the development of certain types of alterations that appear over time, particularly in ashlars. Stone petrography, particularly as regards the chemical composition of the minerals comprising granite, also govern its alteration. Moreover, the commercial term granite often includes other more alkaline rocks generically known as granitoids, whose alterability is higher than in granite per se. The values of some of the physical properties of these rocks, which must be quantified to evaluate their durability, are shown to differ in keeping with their anisotropy. Finally, the forms, causes and mechanisms involved in granite decay are reviewed in the context of its use in building construction.En el artículo se sintetizan los diversos aspectos que inciden en la alteración de las rocas graníticas, cuando estas se utilizan en los edificios, ya sea en forma de sillares o de losetas de revestimiento. Se hace especial hincapié en las anisotropías, fundamentalmente de carácter fisural que suelen presentar los granitos. Estas suelen estar relacionadas con las condiciones estructurales del yacimiento del cual proceden. Dichas anisotropías condicionan el desarrollo de determinadas formas de alteración que con el paso del tiempo se aprecian, sobre todo en los sillares. También se recuerda que la petrografía, y en especial la composición química de los minerales que componen las rocas graníticas, condicionan su alteración, y que dentro del término comercial granito se suelen incluir otras rocas más alcalinas denominadas genéricamente granitoides y más alterables que el granito sensu

  15. 46 CFR 7.55 - Cape Henry, VA to Cape Fear, NC.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Cape Henry, VA to Cape Fear, NC. 7.55 Section 7.55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Atlantic Coast § 7.55 Cape Henry, VA to Cape Fear, NC. (a) A line drawn from Rudee Inlet Jetty Light “2” to...

  16. Radon exhalation rates of some granites used in Serbia

    Directory of Open Access Journals (Sweden)

    Nikolić Mladen D.

    2015-01-01

    Full Text Available In order to address concern about radon exhalation in building material, radon exhalation rate was determined for different granites available on Serbian market. Radon exhalation rate, along with mass exhalation rate and effective radium content were determined by closed chamber method and active continuous radon measurement technique. For this research, special chambers were made and tested for back diffusion and leakage, and the radon concentrations measured were included in the calculation of radon exhalation. The radon exhalation rate ranged from 0.161 Bq/m2h to 0.576 Bq/m2h, the mass exhalation rate from 0.167 Bq/kgh to 0.678 Bq/kgh, while the effective radium content was found to be from 12.37 Bq/kg to 50.23 Bq/kg. The results indicate that the granites used in Serbia have a low level of radon exhalation.

  17. Quantized Ultracold Neutrons in Rough Waveguides: GRANIT Experiments and Beyond

    Directory of Open Access Journals (Sweden)

    M. Escobar

    2014-01-01

    Full Text Available We apply our general theory of transport in systems with random rough boundaries to gravitationally quantized ultracold neutrons in rough waveguides as in GRANIT experiments (ILL, Grenoble. We consider waveguides with roughness in both two and one dimensions (2D and 1D. In the biased diffusion approximation the depletion times for the gravitational quantum states can be easily expressed via each other irrespective of the system parameters. The calculation of the exit neutron count reduces to evaluation of a single constant which contains a complicated integral of the correlation function of surface roughness. In the case of 1D roughness (random grating this constant is calculated analytically for common types of the correlation functions. The results obey simple scaling relations which are slightly different in 1D and 2D. We predict the exit neutron count for the new GRANIT cell.

  18. Lower granite GIS data description and collection guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, J.L.; Evans, B.J.; Perry, E.M.

    1995-12-01

    The Lower Granite Geographic Information System (GIS) was developed jointly by the US Army Corps of Engineers (USCOE) Walla Walla District and the Pacific Northwest Laboratory (PNL). The goal of the project is to use GIS technology to analyze impacts of the drawdown mitigation option on the physical and biological environment of the Lower Granite Reservoir. The drawdown mitigation option is based on the hypothesis that faster juvenile salmon travel to the ocean would result in higher juvenile survival and greater smolt-to-adult return ratios; to accomplish this, reservoir elevations would be lowered to increase channel velocities. Altering the elevation of the reservoirs on the Snake River is expected to have a variety of impacts to the Physical environment including changes to water velocity, temperature, dissolved gases, and turbidity. The GIS was developed to evaluate these changes and the resulting impacts on the anadromous and resident fish of the Snake River, as well as other aquatic organisms and terrestrial wildlife residing in the adjacent riparian areas. The Lower Granite GIS was developed using commercial hardware and software and is supported by a commercial relational database. Much of the initial system development involved collecting and incorporating data describing the river channel characteristics, hydrologic properties, and aquatic ecology. Potentially meaningful data for the Lower Granite GIS were identified and an extensive data search was performed. Data were obtained from scientists who are analyzing the habitats, limnology, and hydrology of the Snake River. The next six sections of this document describe the bathymetry, fish abundance, substrate, sediment chemistry, and channel hydrology data.

  19. Static and kinetic friction of granite at high normal stress

    Science.gov (United States)

    Byerlee, J.D.

    1970-01-01

    Frictional sliding on ground surfaces of granite, angle of sliding planes 30?? and 45??, was investigated as a function of confining pressure. Over the normal stress range of 2-12 kb, the static frictional shear stress ??s follows the relationship ??s = 0??5 + 0?? ??n and the kinetic frictional shear stress ??k was calculated to be ??k = 0??25 + 0??47 ??n. ?? 1970.

  20. Granite rock fragmentation at percussive drilling - experimental and numerical investigation

    OpenAIRE

    Saadati, Mahdi; Forquin, Pascal; Weddfelt, Ken; Larsson, Per-Lennart; Hild, François

    2014-01-01

    International audience; The aim of this study is to numerically model the fracture system at percussive drilling. Due to the complex behavior of rock materials, a continuum approach is employed relying upon a plasticity model with yield surface locus as a quadratic function of the mean pressure in the principal stress space coupled with an anisotropic damage model. In particular, Bohus granite rock is investigated and the material parameters are defined based on previous experiments. This inc...

  1. Lower Granite Dam Smolt Monitoring Program, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Verhey, Peter; Ross, Doug; Morrill, Charles (Washington Department of Fish and Wildlife, Olympia, WA)

    1998-12-01

    The 1998 fish collection season at Lower Granite was characterized by relatively moderate spring flows and spill, moderate levels of debris, cool spring, warm summer and fall water temperatures, and increased chinook numbers, particularly wild subyearling chinook collected and transported. The Fish Passage Center's Smolt Monitoring Program is designed to provide a consistent, real-time database on fish passage and document the migrational characteristics of the many stocks of salmon and steelhead in the Columbia Basin.

  2. Lower Granite Dam Smolt Monitoring Program; 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Verhey, Peter; Witalis, Shirley; Morrill, Charles (Washington Department of Fish and Wildlife, Olympia, WA)

    1998-01-01

    The 1997 fish collection season at Lower Granite was characterized by high spring flows, extensive spill, cool spring and early summer water temperatures and comparatively low numbers of fish, particularly yearling chinook. The Fish Passage Center's Smolt Monitoring Program is designed to provide a consistent, real-time database of fish passage and document the migrational characteristics of the many stocks of salmon and steelhead in the Columbia Basin.

  3. δ30Si systematics in a granitic saprolite, Puerto Rico

    Science.gov (United States)

    Ziegler, Karen; Chadwick, Oliver A.; White, Arthur F.; Brzezinski, Mark A.

    2005-01-01

    Granite weathering and clay mineral formation impart distinct and interpretable stable Si isotope (δ30Si) signatures to their solid and aqueous products. Within a saprolite, clay minerals have δ30Si values ∼2.0‰ more negative than their parent mineral and the δ30Si signature of the bulk solid is determined by the ratio of primary to secondary minerals. Mineral-specific weathering reactions predominate at different depths, driving changes in differing δ30Sipore watervalues. At the bedrock-saprolite interface, dissolution of plagioclase and hornblende creates δ30Sipore water signatures more positive than granite by up to 1.2‰; these reactions are the main contributor of Si to stream water and determine its δ30Si value. Throughout the saprolite, biotite weathering releases Si to pore waters but kaolinite overgrowth formation modulates its contribution to pore-water Si. The influence of biotite on δ30Sipore water is greatest near the bedrock where biotite-derived Si mixes with bulk pore water prior to kaolinite formation. Higher in the saprolite, biotite grains have become more isolated by kaolinite overgrowth, which consumes biotite-derived Si that would otherwise influence δ30Sipore water. Because of this isolation, which shifts the dominant source of pore-water Si from biotite to quartz, δ30Sipore water values are more negative than granite by up to 1.3‰ near the top of the saprolite.

  4. Static and Dynamic Flexural Strength Anisotropy of Barre Granite

    Science.gov (United States)

    Dai, F.; Xia, K.; Zuo, J. P.; Zhang, R.; Xu, N. W.

    2013-11-01

    Granite exhibits anisotropy due to pre-existing microcracks under tectonic loadings; and the mechanical property anisotropy such as flexural/tensile strength is vital to many rock engineering applications. In this paper, Barre Granite is studied to understand the flexural strength anisotropy under a wide range of loading rates using newly proposed semi-circular bend tests. Static tests are conducted with a MTS hydraulic servo-control testing machine and dynamic tests with a split Hopkinson pressure bar (SHPB) system. Six samples groups are fabricated with respect to the three principle directions of Barre granite. Pulse shaping technique is used in all dynamic SHPB tests to facilitate dynamic stress equilibrium. Finite element method is utilized to build up equations calculating the flexural tensile strength. For samples in the same orientation group, a loading rate dependence of the flexural tensile strength is observed. The measured flexural tensile strength is higher than the tensile strength measured using Brazilian disc method at given loading rate and this scenario has been rationalized using a non-local failure theory. The flexural tensile strength anisotropy features obvious dependence on the loading rates, the higher the loading rate, the less the anisotropy and this phenomenon may be explained considering the interaction of the preferentially oriented microcracks.

  5. Dose assessment associated with granite use in residential property

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Andre Luiz do Carmo, E-mail: andre.leal@ifrj.edu.br [Instituto Federal do Rio de Janeiro (IFRJ), Sao Goncalo, RJ (Brazil); Lauria, Dejanira da Costa, E-mail: dejanira@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The radioactivity levels in materials used as building materials have been reported in many countries and relatively high levels of radioactivity have been identified in some materials build (Beretka and Mathew, 1985; Pavlidou et al., 2006; Tzortzis et al., 2003 ; Al-Selah and Al-Berzan, 2007; Kitto et al.,2009 ; Myatt et al., 2010 ). Although is reported in the literature some studies on the levels of radionuclides in granites and the associated doses (Salas, 2003; Ahmed et al., 2006; Bonotto et al, 2009 ; Turhan, 2012; Anjos et al., 2005, 2012), most of assessed dose are related with external exposure data (Anjos et al., 2011, Llope, 2011 ). From the radionuclide concentrations in 10 samples of granite rock, this study evaluated the dose by inhalation of radon from the use of national granites as floor covering, according to the refresh rate of air, porosity, and radon emanation rate of diffusion coefficient by sensitivity analyzes, using the RESRAD-BUILD 3.5 code. As a result, it was found that the higher dose by radon inhalation was 0.058 mSv / year and the Rn-220 isotope is the largest contributor to this route of exposure. (author)

  6. The Early Paleozoic Xitieshan syn-collisional granite in the North Qaidam ultrahigh-pressure metamorphic belt, NW China: Petrogenesis and implications for continental crust growth

    Science.gov (United States)

    Zhao, Zhixin; Wei, Junhao; Fu, Lebing; Liang, Shengnan; Zhao, Shaoqing

    2017-05-01

    Syn-collisional magmatism produced by partial melting of subducted oceanic and continental crust during the continental collision plays an important role in understanding the orogenic evolution and crustal growth. This contribution reports zircon LA-ICPMS U-Pb ages and Hf isotopic compositions, whole rock major and trace elements and Sr-Nd isotopic compositions of syn-collisional Xitieshan intrusion within the North Qaidam ultrahigh-pressure metamorphic (UHPM) belt, to study its petrogenesis and contribution to continental crust growth. LA-ICPMS zircon U-Pb dating of the Xitieshan granite yields magmatic crystallization ages of 441 ± 2 Ma and 442 ± 2 Ma, which are consistent with the peak age of ultrahigh-pressure eclogite-facies metamorphism in the Xiteishan terrane. The temporal correlation between them confirms that the Xitieshan granite was products of syn-collisional magmatism during the continental collision between Qaidam and Qilian Blocks. These granites show high-K calc-alkaline and slightly peraluminous signature, low zirconium saturation temperatures and high contents of K2O with the S-type characteristics. They have rare earth element and trace element patterns resembling those of bulk continental crust, with strong fractionation of light and heavy rare earth elements ((La/Yb)N = 19-26), moderately Eu negative anomalies (δEu = 0.65-0.71) and the obviously Nb, Ta, P and Ti negative anomalies. The Xitieshan granite also exhibits remarkable Sr-Nd isotopic differences (initial 87Sr/86Sr = 0.70920-0.71080 and εNd(t) = - 4.54-4.11) from the contemporaneous granites within North Qaidam UHPM belt. Combined with the positive εHf (t)(0.5-5.3) and ages of inherited zircons (475-518 Ma), the magmatism is best explained as resulting from melting of subducted oceanic and continental crust during continental collision. Isotopic mixing calculations suggest that ca. 28-35% ocean crust and ca. 65-72% continental materials contribute to the origin of the Xitieshan

  7. Cretaceous Gross Spitzkoppe and Klein Spitzkoppe stocks in Namibia: Topaz-bearing A-type granites related to continental rifting and mantle plume

    Science.gov (United States)

    Haapala, I.; Frindt, S.; Kandara, J.

    2007-08-01

    The anorogenic Damaraland intrusive complexes in Namibia belong to the bimodal Paraná-Etendeka Large Igneous Province and comprise mafic, silicic and alkaline plutonic and volcanic rocks that were emplaced into the Neoproterozoic Damara orogenic belt at 124 to 137 Ma. The magmatism was related to the Tristan mantle plume and continental rifting that led to separation of South America from Africa. Silicic plutonic rocks are found in the Gross Spitzkoppe, Klein Spitzkoppe, Erongo, Brandberg, Messum, Cape Cross, and Paresis complexes. The Gross Spitzkoppe and Klein Spitzkoppe stocks consist of texturally distinct types of topaz-bearing biotite (siderophyllite-annite) granites with columbite, zircon, magnetite, and monazite as typical heavy accessory minerals. A bimodal magmatic association is indicated by synplutonic mafic dikes and magmatic mafic inclusions. The stocks have rims of layered aplite-pegmatite stockscheiders against the country rocks. Miarolitic cavities and pegmatite-lined druses with gem-quality topaz and beryl indicate vapor saturation, and hydrothermal activity has locally produced wolframite-bearing greisen. The Spitzkoppe granites are highly evolved, marginally peraluminous (A/CNK 0.95 to 1.09) and characterized by high SiO 2 (74.4 to 78.6 wt.%), Na 2O + K 2O (7.6 to 8.8 wt.%, with K 2O prevailing over Na 2O), F, Rb, and Ga, as well as low MgO, Ba, and Sr. The small but clear differences in REE patterns [(La/Yb) N in Gross Spitzkoppe 2.5 to 7.7 with mean at 4.4, in Klein Spitzkoppe 0.6 to 1.6 with mean at 0.9, more pronounced negative (Eu/Eu *) N anomaly in Klein Spitzkoppe] show that the granites of the Klein Spitzkoppe stock are slightly more evolved than those of the Gross Spitzkoppe stock. Overall, the granites exhibit A-type and within plate characteristics. Available O, Nd and Sr isotope data suggest that the silicic rocks of the anorogenic Damaraland complexes have mixed sources, with plume-related mantle magmas and two types of lower

  8. Some Lexical Aspects of Cape Muslim Afrikaans

    African Journals Online (AJOL)

    Abstract: It is a relatively well known fact that Cape Muslim Afrikaans has its own distinctive pronunciations which at times differ sharply with that of Standard Afrikaans. What is not so well known, is that apart from its core vocabulary, which is derived from Dutch, Cape Muslim Afri- kaans also has a distinctive lexical inventory, ...

  9. Cape Verde in False Color

    Science.gov (United States)

    2007-01-01

    A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this false-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days. This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

  10. Bluish granites from Extremadura (Spain): a radiological evaluation.

    Science.gov (United States)

    Pereira, Dolores; Neves, Luís.; Peinado, Mercedes; Pereira, Alcides; Rodríguez, Leticia; António Blanco, José

    2010-05-01

    We have found in the area of Trujillo (Extremadura, Spain) a variety of striking bluish granites, outcropping within the Plasenzuela pluton. They are all quarried under different names and are characterized by leucocratic minerals such as quartz, feldspar (both potassium and plagioclase), sometimes giving a fenocrystic texture and muscovite, with some biotite. As accessory phases, idiomorphic tourmaline is found. Recently a bluish phosphate distributed in the whole rock was detected, included within most mineral phases and fillings from stressed structures that are cutting the rock. We attribute the bluish color of the granites to this phosphate. Although biotite is almost always transformed to chlorite, the rock gives an excellent response to be polished. Physico-mechanical properties make this bluish granite a perfect option for most applications. Absorption coefficient is rather low and alteration by thermal changes has not been observed. A secondary facies with yellow colour also occurs, spatially close to the topographic surface, and probably represents an alteration product of the original granite. This facies is also commercialized as ornamental stone. A radiological survey was carried out in the field, using a gamma ray spectrometer. The radiological background is quite homogeneous in the pluton, without significant differences between gamma ray fluxes of both facies (altered and non altered). The average contents of U, Th and K2O determined in situ with the spectrometer are 7.4 ppm, 0.8 ppm and 3.67%, respectively (n=15). Using U as a Ra proxy, the I index of the EU technical document 112 can be determined, and results in a value of 0.64 for the referred composition. This implies that the rock can be used without any restrictions for building purposes. However, a marked difference was observed in radon exhalation tests carried out in laboratorial facilities. The dominant blue variety shows radon exhalation rates comprised between 0.02 and 0.04 Bq.kg-1.h-1

  11. SEAFLOOR SEDIMENT CHARACTERISTICS AND HEAVY MINERAL OCCURENCES AT BETUMPAK CAPE AND ADJACENT AREA, BANGKA STRAIT, BANGKA BELITUNG PROVINCE

    Directory of Open Access Journals (Sweden)

    Rohendi Rohendi

    2017-07-01

    Full Text Available Thirty seafloor of sediment samples have been taken by using gravity corer and grab sampler at Betumpak Cape, and adjacent area of Bangka Belitung. The result of grain size analyses show that there are four sediment units: gravelly sand, gravelly muddy sand, silt and silty sand. Identification of Scanning Electron Microscope (SEM image on several samples shows the presence of clay mineral such as smectite, alunite, chlorite etc., may resulted from plagioclase weathering of granite. Based on heavy mineral analyses, its highest content is found at MTK-27 (northwest of Betumpak Cape. High content of apatite (0.94% wt and 1.07% wt is found on coarse sand fractions (115-170 mesh at MTK-29 (northeast Ular Cape and MTK-30 (north of Ular Cape. Generally, the heavy mineral accumulation is occurred on medium sand fraction (60-80 mesh as magnetite (7.86% wt, ilmenite (4.9% wt and zircon (1.32% wt. Based on these data, it shows that heavy mineral is accumulated on medium to coarse sand.

  12. Petrography and geochemistry of the topaz-bearing granite stocks in Artjärvi and Sääskjärvi, western margin of the Wiborg rapakivi granite batholith

    Directory of Open Access Journals (Sweden)

    Sari Lukkari

    2002-01-01

    Full Text Available The Artjärvi and Sääskjärvi granite stocks at the western margin of the Wiborg rapakivi batholith are multiphase rapakivi granite intrusions in which the most evolved phase is topaz-bearing granite. The Artjärvi stock is composed of porphyritic and even-grained biotite granite and even-grained topaz granite, and the Sääskjärvi stock comprises even-grained biotite granite and porphyritic topazgranite. The granites are metaluminous to peraluminous A-type granites, showing within-plate (WPG geochemical characteristics. The topaz granites from the Artjärvi and Sääskjärvi stocks are petrographically and geochemically similar to other topaz-bearing rapakivi granites in Finland. The anomalous geochemistry of the topaz granite is essentially magmatic; postmagmatic reactions have only slightly modified its composition. Greisen veins, some of which are mineralized, are widely found associated with the Artjärvi and Sääskjärvi stocks.The most characteristic feature of the Artjärvi granite stock is a stockscheider at the roof contact of the topaz granite. The stockscheider is composed of schlieren layering and pegmatite layers parallel to the contact. The most probable mechanism for the formation of the schlieren layering is velocity-gradient sorting parallel to the flow, which led to accumulation of mafic minerals along the upper contact of the topaz granite. Cooling and contraction of the topaz granite formed fractures parallel to the roof contact and the residual pegmatite magmas were injected along the fractures forming pegmatite layers. Textures like graphic intergrowths, aplitic groundmass and fan-shaped alkali feldspar crystals associated with the Artjärvi porphyritic biotite granite and pegmatite indicatecrystallization from undercooled magma. Miarolitic cavities found in the porphyritic biotite granite and topaz granite indicate at least local volatile saturation.

  13. New data on the age and nature of the Khan-Bogd alkaline granites, Mongolia

    Science.gov (United States)

    Gerdes, A.; Kogarko, L. N.; Vladykin, N. V.

    2017-11-01

    New age dating (291 Ma) was obtained for one of the largest alkaline granite massifs in the world, the Khan-Bogd Massif (Mongolia). For the first time, apart from zircon, other zirconium silicates, elpidite and armstrongite, have been analyzed. Our determinations showed the highly depleted nature of the mantle sources of granites with ɛNd = 12. All the studied Zr-silicates demonstrate positive Eu anomalies in the REE patterns, which indicate a low oxidation potential during alkaline granite formation.

  14. Determination of geochemical affinities of granitic rocks from the Aue-Schwarzenberg zone (Erzgebirge, Germany) by multivariate statistics

    Science.gov (United States)

    Forster, H.-J.; Davis, J.C.

    2000-01-01

    Variscan granites of the Erzgebirge region can be effectively classified into five genetically distinct major groups by canonical analysis of geochemical variables. The same classification procedure, when applied to small plutons in the Aue-Schwarzenberg granite zone (ASGZ), shows that all ASGZ granites have compositional affinities to low-F biotite or low-F two-mica granite groups. This suggests that the ASGZ granites were emplaced during the first, late-collisional stage of silicic magmatism in the region, which occurred between about 325 and 318 Ma. The numerous biotite granite bodies in the zone are geochemically distinct from both the neighboring Kirchberg granite pluton and the spatially displaced Niederbobritzsch biotite granite massif. Instead, these bodies seem to constitute a third sub-group within the low-F biotite granite class. The ASGZ biotite granites represent three or more genetically distinct bodies, thus highlighting the enormous compositional variability within this group of granites. Least evolved samples of two-mica granites from the ASGZ apparently reflect the assimilation of low-grade metamorphic country rocks during emplacement, altering the original composition of the melts by enhancing primary Al content. The same genesis is implied for the rare "cordierite granite" facies of the Bergen massif, the type pluton for the low-F two-mica granite group in the Erzgebirge.

  15. The rapakivi granite plutons of Bodom and Obbnäs, southern Finland: petrography and geochemistry

    Directory of Open Access Journals (Sweden)

    Kosunen, P.

    1999-12-01

    Full Text Available The Obbnäs and Bodom granite plutons of southernmost Finland show the typical petrographic and geochemical features of the Proterozoic rapakivi granites in Finland and elsewhere: they cut sharply across the 1900 Ma Svecofennian metamorphic bedrock and have the geochemical characteristics of subalkaline A-type granites. The Bodom pluton is composed of porphyritic granites (hornblende-, hornblende-biotite-, and biotite-bearing varieties and an even-grained granite that probably represent two separate intrusive phases. This lithologic variation does not occur in the Obbnäs pluton, which is almost entirely composed of porphyritic hornblende-biotite granite that gradually becomes more mafic to the southwest. Three types of hybrid granitoids resulting from magma mingling and mixing occur on the southwestern tip of the Obbnäs peninsula. The Bodom granites are syenogranites, whereas the composition of the Obbnäs granite varies from syeno- to monzogranite. The main silicates of both the Bodom and Obbnäs granites are quartz, microcline, plagioclase (An1541, biotite (siderophyllite, and generally also amphibole (ferropargasite or hastingsite. Plagioclase-mantled alkali feldspar megacrysts are absent or rare. The accessory minerals are fluorite, allanite, zircon, apatite, and iron-titanium oxides; the Obbnäs granite also contains titanite. The Bodom and Obbnäs granites are metaluminous to weakly peraluminous, with average A/CNK of 1.00 and 1.05, respectively, have high Fe/Mg (average FeOtot/[FeOtot+MgO] is 0.94 for the Bodom and 0.87 for the Obbnäs granites, and high Ga/Al (3.78 to 5.22 in Bodom and 2.46 to 4.18 in Obbnäs. The REE contents are high with LREE-enriched chondrite-normalized patterns and moderate (Obbnäs to relatively strong (Bodom negative Eu-anomalies. The Obbnäs granite is enriched in CaO, TiO2, MgO, and FeO, and depleted in SiO2 and K2O compared to the Bodom granites. Also, there are differences in the Ba, Rb, and Sr contents of

  16. Tecer sobe no ranking da Capes

    Directory of Open Access Journals (Sweden)

    José Aparecido

    2013-11-01

    Full Text Available Surpresa ainda maior foi verificar que prosseguimos no rumo da consolidação, crescendo no ranking – chegando a B3 em alguns campos, como pode ser visto no portal de buscas do Qualis Capes http://qualis.capes.gov.br/webqualis/principal.seamhttp://qualis.capes.gov, que apresenta nossa classificação abaixo:   B3 ADMINISTRAÇÃO, CIÊNCIAS CONTÁBEIS E TURISMO B4 CIÊNCIAS SOCIAIS APLICADAS I B4 EDUCAÇÃO B4 INTERDISCIPLINAR B5 DIREITO B5 HISTÓRIA C CIÊNCIA DA COMPUTAÇÃO

  17. Classification, mineralogical and geochemical variations in pegmatites of the Cape Cross-Uis pegmatite belt, Namibia

    Science.gov (United States)

    Fuchsloch, Warrick C.; Nex, Paul A. M.; Kinnaird, Judith A.

    2018-01-01

    The Pan African aged Damara Orogen in Namibia is host to the Cape Cross-Uis pegmatite belt, one of several NE-trending pegmatite belts which host Li, Nb, Ta and Sn mineralisation. Field mapping and structural analysis of thirty seven pegmatite bodies has shown that the pegmatites intrude along crustal weaknesses such as fold axes and bedding planes, predominantly following the approximate NE orientated regional structural fabric. The lack of deformation together with cross-cutting relationships mapped, suggest that pegmatites were emplaced during post-tectonic extension that resulted from end-orogeny crustal relaxation. Based on mineralogy, geochemistry and ore mineralogy, three groups of pegmatites are distinguished within the Cape Cross-Uis belt. (1) The most common are the unzoned Nb-Ta-Sn type with mineralised alteration areas in the form of greisenised and albitised zones that occur sporadically in the pegmatites in various morphologies. (2) The garnet-tourmaline, crudely zoned pegmatites are slightly less common. They are granite-hosted and differ from other pegmatite types in terms of their low Rb, Sr, Nb, Ta, Sn, Cs (lithium-bearing pegmatites are rare but the most complex. They are subdivided into two groups: The Li-Nb-Ta-Sn spodumene-bearing pegmatites of the Karlowa swarm and the Li-Nb-Ta-Sn-Be petalite-bearing pegmatites of the Strathmore swarm. They are highly fractionated with typical values of Nb (206 ppm), Ta (185 ppm) and Sn (10,016 ppm). There is no spatial distribution or regional zonation of the pegmatites type relative to granite outcrops within the belt. Contrasting geochemical fractionation patterns and the lower concentrations of REE in pegmatites than in granites suggests that pegmatites resulted from varying degrees of partial melting of a muscovite-ilmenite-bearing source. The Sn, Nb and Ta in pegmatites is likely to have originated from this source rather than from assimilation of metasedimentary host rocks as clear fractionation trends

  18. The Origin of Graphic Granite: New Insights from Electron Backscatter Diffraction (EBSD) Analyses

    Science.gov (United States)

    Xu, H.; Wu, Y.

    2016-12-01

    Graphic granite, found predominantly in granitic pegmatite, is a leucocratic granitic rock consisting of an intimate intergrowth of alkali feldspar and quartz with a distinctive texture as ancient cuneiform writing when viewed in certain cross sections. Deciphering the graphic texture is important for understanding its origin and the crystallization process of granitic rocks. In this study, we present investigations on petrology, mineral composition, crystallographic relationship and topotaxy of quartz and alkali feldspar in graphic granites from the Fangshan adakitic pluton, Beijing, north China and the Luotian dome in the Northern Dabie Mountains, central China. The euhedral to subhedral coarse-grained feldspar host in graphic granite can be alkali feldspar or plagioclase. Microscopically, the feldspar host is usually a perthite, which is decomposed into irregular intergrowth of sodic and potassic feldspar. The volume content of quartz usually ranges from 20% to 45%, and the composition of feldspar in graphic granite depends greatly on the formation conditions. However, the quartz-feldspar ratio and the composition of feldspar in graphic granite are relatively stable in coeval graphic granites in the same area. The majority of the quartz grains undergrown with host feldspar are in the form of sub-parallel tabular, long rods and unconnected dendritic crystals, which only shows a distinctive graphic texture in certain cross sections. Under cross polarized light microscopy, multiple domains of quartz grains exhibit a nearly simultaneous extinction within a single crystal of feldspar. The crystallographic orientations of the quartz grains and the host feldspar were measured using the electron backscatter diffraction (EBSD) technique. Statistical analyses indicate a definite crystallographic orientation relationship between the majority of graphic quartz grains and the host feldspar in that [11-23]Quartz parallel to [001]Feldspar. Moreover, Dauphiné twin of quartz

  19. NAMMA PRAIA CAPE VERDE RADIOSONDE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Praia Cape Verde Radiosonde data used Sippican MarkIIa DGPS (LOS) radiosondes, which were launched in support of NASA African Monsoon Multidisciplinary...

  20. EAARL Topography-Cape Cod National Seashore

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Elevation maps (also known as Digital Elevation Models or DEMs) of Cape Cod National Seashore were produced from remotely-sensed, geographically-referenced elevation...

  1. Cape Canaveral, Kennedy Space Center, Florida

    Science.gov (United States)

    1989-01-01

    This overhead view of the central eastern shore of Florida shows the Cape Canaveral and Kennedy Space Center (28.5N, 80.5W), where all of the NASA manned space missions originate. Sprinkled along the jutting cape are a number of KSC launch pads and the nearby Space Shuttle Landing Facility. Merritt Island, just south of Kennedy Space Center is where the spacecraft liftoff tracking station is located. Orlando is on the left edge of photo.

  2. A-type granite and the Red Sea opening

    Science.gov (United States)

    Coleman, R.G.; DeBari, S.; Peterman, Z.

    1992-01-01

    Miocene-Oligocene A-type granite intrudes the eastern side of the Red Sea margin within the zone of extension from Jiddah, Saudi Arabia south to Yemen. The intrusions developed in the early stages of continental extension as Arabia began to move slowly away from Africa (around 30-20 Ma). Within the narrow zone of extension silicic magmas formed dikes, sills, small plutons and extrusive equivalents. In the Jabal Tirf area of Saudi Arabia these rocks occur in an elongate zone consisting of late Precambrian basement to the east, which is gradually invaded by mafic dikes. The number of dikes increases westward until an igneous complex is produced parallel to the present Red Sea axis. The Jabal Tirf igneous complex consists of diabase and rhyolite-granophyre sills (20-24 Ma). Although these are intrusine intrusive rocks their textures indicate shallow depths of intrusion (peralkaline and metaluminous granitic magmas involved both fractio??nation and partial melting as they ascended through the late Precambrian crust of the Arabian plate. ?? 1992.

  3. Comparative study of dark patinas on granitic outcrops and buildings

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, B. [Dpto. Edafologia y Quimica agricola, Fac. Farmacia, Univ. Santiago de Compostela, 15782-Santiago de Compostela (Spain)]. E-mail: edprieto@usc.es; Aira, N. [Dpto. Edafologia y Quimica agricola, Fac. Farmacia, Univ. Santiago de Compostela, 15782-Santiago de Compostela (Spain); Silva, B. [Dpto. Edafologia y Quimica agricola, Fac. Farmacia, Univ. Santiago de Compostela, 15782-Santiago de Compostela (Spain)

    2007-08-01

    Formation of dark patinas on rocky surfaces is mainly related to the deposition of gases and particles and to sulphation mechanisms. In the present study, samples of dark patinas taken from granitic outcrops and from granitic buildings were examined in an attempt to understand the mechanisms of their formation. The outcrops are located in non-polluted areas and are characterized by the absence of any extraneous material that provides calcium, such as e.g. mortar. The buildings are located in areas with low levels of pollution. The climate in the study area favours proliferation of microorganisms. Important differences between the patinas sampled from outcrops and from buildings were observed, as the former are of biological origin and the latter of anthropogenic origin. Although the levels of pollution are low in the sampling area, sulphur was present in all of the samples from urban buildings. Sulphur was not present in patinas from outcrops or in patinas from monuments that are assumed to behave as outcrops (dolmens), although the latter are also of anthropogenic origin. Finally, the patinas were found to be formed by elements accumulated on the surface and not from elements contained within the rock itself.

  4. A new skink (Scincidae: Liburnascincus) from rocky habitat on Cape York, northeast Australia.

    Science.gov (United States)

    Hoskin, Conrad J; Couper, Patrick J

    2015-07-31

    The genus Liburnascincus is composed of saxicoline skinks restricted to northeast Australia. This small radiation consists of one widespread species, L. mundivensis, found in a variety of rocky habitats in eastern Queensland, and two localized species, L. coensis and L. scirtetis, restricted to granite boulder habitats on Cape York Peninsula, in north Queensland. Here we describe a fourth species, L. artemis sp. nov., from the Bamboo Range, a low rocky range on Cape York. As for other Liburnascincus, the new species is a saxicoline skink that is active on boulder surfaces primarily early and late in the day. Liburnascincus artemis sp. nov. is most similar to L. mundivensis but can be diagnosed based on longer limbs, higher toe and finger lamellae counts, lower midbody scale count, and other aspects of morphology, scalation and colour pattern. Liburnascincus artemis sp. nov. is currently known from a very small area but further surveys will likely extend the range. It is geographically separated from L. mundivensis to the south by unsuitable habitat in the Laura region, but it may abut the range of L. coensis to the north. Despite a small distribution, L. artemis sp. nov. occurs at high density at the known sites and appears to be currently secure. In this paper we also discuss the distributions and biogeography of Liburnascincus more broadly.

  5. Permian ultrafelsic A-type granite from Besar Islands group, Johor ...

    Indian Academy of Sciences (India)

    high age (1141 Ma). 5. Geochemistry. 5.1 Methods. Nine representative granite samples were collected from the Hujung (2), Tengah (2) and Besar (5) islands. All samples were crushed ... Zircon U–Pb concordia and weighted average diagram for sample (a) TG4 and (b) BES5 from the Besar granites. (figure 13), the rocks ...

  6. Speleothem and biofilm formation in a granite/dolerite cave, Northern Sweden

    DEFF Research Database (Denmark)

    Sallstedt, T.; Ivarsson, M.; Lundberg, J.

    2014-01-01

    Tjuv-Antes grotta (Tjuv-Ante's Cave) located in northern Sweden is a round-abraded sea cave ('tunnel cave'), about 30 m in length, formed by rock-water abrasion in a dolerite dyke in granite gneiss. Abundant speleothems are restricted to the inner, mafic parts of the cave and absent on granite...

  7. Rootless calc-silicate folds in granite: An implication towards syn to ...

    Indian Academy of Sciences (India)

    36

    Northern extremity of Godhra granite is. 10 marked by the contact with the Lunavada Group of rocks. The field evidence for granite and. 11 related pegmatites intruding foliation in schists of Kadana Formation, Lunavada Group,. 12 indicates that the intrusion continued even after D3 deformation of the Lunavada region. 13.

  8. 2005 dossier: granite. Tome: architecture and management of the geologic disposal; Dossier 2005: granite. Tome architecture et gestion du stockage geologique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the geologic disposal of high-level and long-lived radioactive wastes in granite formations. Content: 1 - Approach of the study: main steps since the December 30, 1991 law, ANDRA's research program on disposal in granitic formations; 2 - high-level and long-lived (HLLL) wastes: production scenarios, waste categories, inventory model; 3 - disposal facility design in granitic environment: definition of the geologic disposal functions, the granitic material, general facility design options; 4 - general architecture of a disposal facility in granitic environment: surface facilities, underground facilities, disposal process, operational safety; 5 - B-type wastes disposal area: primary containers of B-type wastes, safety options, concrete containers, disposal alveoles, architecture of the B-type wastes disposal area, disposal process and feasibility aspects, functions of disposal components with time; 6 - C-type wastes disposal area: C-type wastes primary containers, safety options, super-containers, disposal alveoles, architecture of the C-type wastes disposal area, disposal process in a reversibility logics, functions of disposal components with time; 7 - spent fuels disposal area: spent fuel assemblies, safety options, spent fuel containers, disposal alveoles, architecture of the spent fuel disposal area, disposal process in a reversibility logics, functions of disposal components with time; 8 - conclusions: suitability of the architecture with various types of French granites, strong design, reversibility taken into consideration. (J.S.)

  9. 2005 dossier: granite. Tome: safety analysis of the geologic disposal; Dossier 2005: granite. Tome analyse de surete du stockage geologique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the safety aspects of the geologic disposal of high-level and long-lived (HLLL) radioactive wastes in granite formations. Content: 1 - safety approach: context and general goal, references, design approach by safety functions, safety approach during the construction-exploitation-observation-closure phase, safety analysis during the post-closure phase; 2 - general description: HLLL wastes, granitic environment, general structure of the architecture of a disposal facility; 3 - safety functions and disposal design: general context, safety functions of the long-term disposal, design dispositions retained to answer the functions; 4 - operational safety: people's protection, radiological risks during exploitation, risk analysis in accident situation; 5 - qualitative safety analysis: methodology, main results of the analysis of the features, events and processes (FEP) database; 6 - disposal efficiency evaluation during post-closure phase: calculation models, calculation tools used for the modeling of radionuclides transport, calculation results and main lessons. (J.S.)

  10. A fractal derivative constitutive model for three stages in granite creep

    Directory of Open Access Journals (Sweden)

    R. Wang

    Full Text Available In this paper, by replacing the Newtonian dashpot with the fractal dashpot and considering damage effect, a new constitutive model is proposed in terms of time fractal derivative to describe the full creep regions of granite. The analytic solutions of the fractal derivative creep constitutive equation are derived via scaling transform. The conventional triaxial compression creep tests are performed on MTS 815 rock mechanics test system to verify the efficiency of the new model. The granite specimen is taken from Beishan site, the most potential area for the China’s high-level radioactive waste repository. It is shown that the proposed fractal model can characterize the creep behavior of granite especially in accelerating stage which the classical models cannot predict. The parametric sensitivity analysis is also conducted to investigate the effects of model parameters on the creep strain of granite. Keywords: Beishan granite, Fractal derivative, Damage evolution, Scaling transformation

  11. Mafic microgranular enclaves (MMEs) in amphibole-bearing granites of the Bintang batholith, Main Range granite province: Evidence for a meta-igneous basement in Western Peninsular Malaysia

    Science.gov (United States)

    Quek, Long Xiang; Ghani, Azman A.; Chung, Sun-Lin; Li, Shan; Lai, Yu-Ming; Saidin, Mokhtar; Amir Hassan, Meor H.; Muhammad Ali, Muhammad Afiq; Badruldin, Muhammad Hafifi; Abu Bakar, Ahmad Farid

    2017-08-01

    Mafic microgranular enclaves (MMEs) with varying sizes are a common occurrence in porphyritic amphibole-bearing granite of the Bintang batholith, which is part of the Main Range granite province. The MMEs of the amphibole-bearing granite are significant as they are related to the I-type granitoids within the Main Range granite province. Petrographic observations indicate the MMEs are mantled with coarse mafic crystals on the rim and contain similar minerals to the host (biotite + plagioclase + K-feldspar + pyroxene + amphibole), but in different proportions. Geochemical analyses indicate the MMEs are shoshonitic with mg# comparable to the granite host. Substantial similarities exist between the MMEs and granite with regards to the normalized rare earth element patterns and trace elements variation diagrams. The MMEs and granite are not completely coeval as the MME zircon U-Pb age (224.3 ± 1.2 Ma) is slightly older than its granite host zircon U-Pb age (216.2 ± 1.0 Ma). The age difference is also observed from the unusual 500 m-long Tiak MME and another amphibole-bearing granite sample from the south of the pluton, which yield 221.8 ± 1.1 Ma and 217.4 ± 1.0 Ma respectively. The oldest inherited zircons found in the MME and granite are 2.0 Ga and 1.3 Ga respectively, while the oldest xenocrystic zircons found in the MME and granite are 2.5 Ga and 1.5 Ga respectively. Identical negative εHf(t) values from zircon U-Pb and Lu-Hf analysis for a MME-granite pair indicates the rocks were generated from a similar, ancient source in the basement. Combining the results, we suggest that incongruent melting of an ancient protolith played an important part in the evolution of the MMEs and granite and the MMEs characteristics are best explained as restite. The zircon Hf model age (two-stage) and the I-type peritectic and restitic mineral assemblages in the MMEs further describe the protolith as Early Proterozoic-Late Archean (≈2.5 Ga) meta-igneous rock. This shows the

  12. Gypsum-induced decay in granite monuments in Northwestern Spain

    Directory of Open Access Journals (Sweden)

    Silva Hermo, B.

    2010-03-01

    Full Text Available One of the most common forms of decay in granite monuments is the detachment of the superficial layer of the stone (plaques, plaquettes and scales. Previous studies of granite monuments in the northwest Iberian Peninsula revealed a direct relation between this type of weathering and the presence of calcium sulphate, and a mechanism whereby the salt causes this type of decay was suggested. In the present study, various hypotheses as regards the origin of the gypsum found in granite monuments are proposed. The study involved analysis of the contents of ions soluble in water, the results of X-ray diffraction analyses and the ratios of CaO/SO3 in samples of stone, mortar and deposits collected from different monuments. It was concluded that in most cases the gypsum originated from old paintworks or/and from the joint mortars, although inputs from other sources cannot be discounted, as discussed

    Una de las formas de deterioro más frecuente en los monumentos graníticos es la separación de la capa superficial de la piedra (placas, plaquetas y escamas. En trabajos anteriores centrados en monumentos del noroeste de la Península Ibérica, se constató la relación directa entre esta forma de alteración y la presencia de sulfato de calcio y se propuso el mecanismo a través del cual esta sal provoca este tipo de deterioro. En este trabajo se plantean varias hipótesis acerca del origen del yeso encontrado en monumentos graníticos. Para ello se comparan los contenidos de iones solubilizados en agua, los resultados de difracción de rayos X y las relaciones OCa/SO3 de muestras de piedra, morteros y depósitos recogidas en diferentes monumentos. Se llega a la conclusión de que en la mayor parte de los casos el yeso procede de antiguas pinturas o de revestimientos superficiales y de los morteros de juntas entre sillares, pero no se puede descartar la contribución de otros aportes, los cuales se discuten también en este artículo.

  13. Mineralogical Control on Microbial Diversity in a Weathered Granite?

    Science.gov (United States)

    Gleeson, D.; Clipson, N.; McDermott, F.

    2003-12-01

    Mineral transformation reactions and the behaviour of metals in rock and soils are affected not only by physicochemical parameters but also by biological factors, particularly by microbial activity. Microbes inhabit a wide range of niches in surface and subsurface environments, with mineral-microbe interactions being generally poorly understood. The focus of this study is to elucidate the role of microbial activity in the weathering of common silicate minerals in granitic rocks. A site in the Wicklow Mountains (Ireland) has been identified that consists of an outcrop surface of Caledonian (ca. 400 million years old) pegmatitic granite from which large intact crystals of variably weathered muscovite, plagioclase, K-feldspar and quartz were sampled, together with whole-rock granite. Culture-based microbial approaches have been widely used to profile microbial communities, particularly from copiotrophic environments, but it is now well established that for oligotrophic environments such as those that would be expected on weathering faces, perhaps less than 1% of microbial diversity can be profiled by cultural means. A number of culture-independent molecular based approaches have been developed to profile microbial diversity and community structure. These rely on successfully isolating environmental DNA from a given environment, followed by the use of the polymerase chain reaction (PCR) to amplify the typically small quantities of extracted DNA. Amplified DNA can then be analysed using cloning based approaches as well as community fingerprinting systems such as denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (TRFLP) and ribosomal intergenic spacer analysis (RISA). Community DNA was extracted and the intergenic spacer region (ITS) between small (16S) and large (23S) bacterial subunit rRNA genes was amplified. RISA fragments were then electrophoresed on a non-denaturing polyacrylamide gel. Banding patterns suggest that

  14. Determination of diffusion and sorption properties of granitic rock

    Energy Technology Data Exchange (ETDEWEB)

    Hoelttae, P.; Siitari-Kauppi, M.; Kylloenen, J. [University of Helsinki, Department of Chemistry, Laboratory of Radiochemistry, P.O.Box 55, FIN-00014 University of Helsinki (Finland); Poteri, A. [VTT Processes, Nuclear Energy, P.O.Box 1608, FIN-02044 VTT (Finland)

    2005-07-01

    Full text of publication follows: Crystalline rock is being considered as a host medium for repository of highly radioactive spent nuclear fuel in Finland and elsewhere. Rock-core column experiments were introduced to estimate the diffusion and sorption properties of Kuru Gray granite which was used in block-scale experiments. Results of this work will be used to estimate radionuclide transport times and retardation parameters in the fracture before block experiments. Rock-core columns were constructed from drill-hole cores drilled orthogonal to the fracture of the granite block. Two of the cores have been glued together to form about 75 cm and 68 cm rods which were placed inside a tube. Flow channel is formed in 0.5 mm gap between the core and the tube. In this work a set of tracer experiments were carried out using same tracers than in block experiments - dye tracer uranin, and radioactive non-sorbing and sorbing tracers ({sup 22}Na, {sup 85}Sr). Water was pumped through the column, tracers were injected into the water flow and quantitatively collected for determining the break-through the tracer. Water used in all experiments was synthetic granitic groundwater which was equilibrated with crushed rock material. Main cation concentrations were followed by atomic adsorption spectroscopy determinations. The total porosity and the surface areas of mineral grains available for sorption and migration of species have been determined by the {sup 14}C-PMMA method. Pore apertures and geometry in mineral phases were analysed by field emission scanning electron microscopy (FESEM) and the minerals and sorbed tracer were quantified by energy dispersive X-ray micro analysis (EDX). The surface area of the solid rock was determined by the B.E.T. method. Transport of tracers was modelled using an advection-dispersion model added with matrix diffusion. Predictive calculations and experimental results showed that matrix diffusion for non-sorbing tracers began to be observable when

  15. Geologic history of Cape Cod, Massachusetts

    Science.gov (United States)

    ,

    1976-01-01

    Cape Cod, a sandy peninsula built mostly during the Ice Age, juts into the Atlantic Ocean like a crooked arm. Because of its exposed location, Cape Cod was visited by many early explorers. Although clear-cut evidence is lacking, the Vikings may have sighted this land about 1,000 years ago. It was visited by Samuel de Champlain in 1605, and his detailed descriptions and charts have helped present-day scientists to determine the rate of growth of Nauset Beach marsh and Nauset spit. Bartholomew Gosnold, a lesser known explorer, settled for a short time on the Elizabeth Islands to the southwest and gave Cape Cod its name in 1602. The Pilgrims first landed in America on the tip of Lower Cape Cod after they were turned back from their more southerly destination by shoals between Cape Cod and Nantucket Island. On Cape Cod they found potable water and food and had their first fight with the natives. The Pilgrims, however, decided that this land was too isolated, too exposed, and too sandy to support them, and they sailed across Cape Cod Bay to establish Plymouth. These features remain today. Small villages are separated by large areas of forest, dune, beach, and marsh. This unspoiled natural beauty makes Cape Cod one of the most favored vacation areas for the people living in the thickly settled Northeastern States. Cape Cod is of particular interest to geologists because it was formed by glaciers very recently in terms of geologic time. During the Great Ice Age, (the Pleistocene Epoch which began 2 to 3 million years ago), glaciers advanced from the north into the temperate regions of the Earth. Glacial ice covered the land at least four times. Each advance was accompanied by a worldwide lowering of sea level because the source of the ice was water from the seas. When the glaciers melted, the climate and sea level were probably much like they are today. In fact, some scientists believe that the Earth is presently between glacial episodes and that ice once again will

  16. Geoscience parameter data base handbook: granites and basalts

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

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

  17. Age of granites of Wrangel Island metamorphic complex

    Science.gov (United States)

    Luchitskaya, Marina; Sergeev, Sergey; Sokolov, Sergey; Tuchkova, Marianna

    2014-05-01

    Within huge arctic shelf of Eastern-Siberian and Chukchi seas the metamorphic basement (Wrangel complex, Berri Formation) is exposed only on the Wrangel Island. There are different points of views on the age of metamorphic rocks of Wrangel complex (Berri Formation): (1) Neoproterozoic (Kameneva, 1970; Ageev, 1979; Kos'ko et al., 1993, 2003), (2) Devonian (Til'man et al., 1964, 1970; Ganelin, 1989). Metamorphic basement is represented by stratified complex, composed of dislocated metavolcanic, metavolcaniclastic and metasedimentary rocks (schists, metasandstones, metaconglomerated) with single lenses and layers of carbonate rocks (Wrangel Island…, 2003). Among basement rocks in the central part of Wrangel Island there are felsic intrusive bodies. They form small tabular bodies from tens centimeters to 70-80 meters in thickness, rarely dikes and small stocks (up to 20 x 30 m) and are composed of granite-porphyres, rarely muscovite porphyr-like granites and granosyenites (Wrangel Island…, 2003). The age of intrusions allow to determine the age of basement formation. Earlier the age of intrusions was determined by different methods and correlated to the boundary between Neoproterozoic and Paleozoic: K-Ar 570-603 Ma, Pb-Pb 590±50 Ma (S.M. Pavlov, Institute of Precambrian Geology and Geochronology, USSR Academy of Sciences), Rb-Sr 475±31 Ma (I.M.Vasil'eva, Institute of Precambrian Geology and Geochronology, USSR Academy of Sciences), U-Pb 609, 633, 677 Ma (Geological Survey of Canada) (Wrangel Island…, 2003; Kos'ko et al., 1993; Cecile et al., 1991). In the lower part of metamorphic rocks of Wrangel complex there are conformable tabular bodies of gneissosed and foliated granitoides. The latter are meramorphosed and transformed in biotite-muscovite-feldspar-quartz-sericite and muscovite-feldspar-quartz-sericite gneisses and schists, where relics of primary minerals (quartz, plagioclase, potassium feldspar, rarely biotite and muscovite) and equigranular granitic

  18. Radon release from granites in south-west England

    CERN Document Server

    Poole, J

    2001-01-01

    accessory minerals. The enhancement of surface area was attributed to the alteration of feldspar to sericite. This has implications for the release of radon. It is thought that the large surface area provides a sink for the adsorption of radon, retaining it in the rock structure. This radon retention explains the paradoxical decline in radon release at small particle size/large specific surface area. Various mechanisms for radon emanation are discussed with reference to the Cornubian granites. It is shown that, based on the measured specific surface areas, inter-crystalline diffusion is a slow process and not a significant contributor to overall radon release (0.01%). Approximately 1% of the total radon produced can be attributed to direct recoil processes, based on the calculated recoil ranges (36 nm). The remainder was attributed to diffusion processes through crystal imperfections and dislocations. The microscopic scale model developed here is extended to the macroscopic scale through examination of the la...

  19. Laboratory Simulation of Flow through Single Fractured Granite

    Science.gov (United States)

    Singh, K. K.; Singh, D. N.; Ranjith, P. G.

    2015-05-01

    Laboratory simulation on fluid flow through fractured rock is important in addressing the seepage/fluid-in-rush related problems that occur during the execution of any civil or geological engineering projects. To understand the mechanics and transport properties of fluid through a fractured rock in detail and to quantify the sources of non-linearity in the discharge and base pressure relationship, fluid flow experiments were carried out on a cylindrical sample of granite containing a `single rough walled fracture'. These experiments were performed under varied conditions of confining pressures, σ 3 (5-40 MPa), which can simulate the condition occurring about 1,000 m below in the earth crust, with elevated base pressure, b p (up to 25 MPa) and by changing fracture roughness. The details of the methodologies involved and the observations are discussed here. The obtained results indicate that most of the data in the Q verses b p plot, fall on the straight line and the flow through the single fracture in granite obeys Darcy's law or the well-known "cubic law" even at high value of b p (=4 MPa) and σ 3 (=5 MPa) combination. The Reynolds number is quite sensitive to the b p, σ 3 and fracture roughness, and there is a critical b p, beyond which transition in flow occurs from laminar to turbulent. It is believed that such studies will be quite useful in identifying the limits of applicability of well know `cubic law', which is required for precise calculation of discharge and/or aperture in any practical issues and in further improving theoretical/numerical models associated with fluid flow through a single fracture.

  20. Ornamental granite durability: evaluation of damage caused by salt crystallization

    Directory of Open Access Journals (Sweden)

    Ordaz, J.

    2008-06-01

    Full Text Available The salt crystallization test is used to evaluate damage caused by soluble salts that penetrate stone and subsequently crystallize in its voids (pores or cracks.The present article discusses the findings for four ornamental granites (gris alba, grissal, rosa porriño and rosavel tested to European and Spanish standard UNE-EN 12370.Since the rocks studied had an open porosity of less than 5%, their weight loss was practically nil. Nonetheless, certain physical properties such as wave propagation, surface roughness and colour were found to vary after testing.The authors feel that durability in such stones should be based not on weight loss alone, but on the other properties mentioned as well, particularly in the case of granite that is to be used for cladding in exteriors.El ensayo de cristalización de sales se utiliza para valorar los daños provocados por las sales solubles que penetran en la roca, cuando éstas cristalizan en sus espacios vacíos (poros o fisuras.En este trabajo se ha valorado el comportamiento de cuatro granitos ornamentales de Galicia (Gris Alba, Grissal, Rosa Porriño y Rosavel sometidos al ensayo normalizado UNE-EN 12370.Las rocas estudiadas tienen una porosidad abierta inferior al 5%; por ello, la pérdida de masa es prácticamente inexistente. Sin embargo, algunas propiedades físicas como la velocidad de propagación de ondas, la rugosidad superficial y el color experimentan variaciones a lo largo de los ciclos.Los autores proponen que para evaluar debidamente la durabilidad de este tipo de rocas no sólo debe tenerse en cuenta la pérdida de masa, sino que también deben medirse las propiedades mencionadas, especialmente si los granitos van a ser utilizados para revestimiento de exteriores.

  1. Solving Abel’s Type Integral Equation with Mikusinski’s Operator of Fractional Order

    Directory of Open Access Journals (Sweden)

    Ming Li

    2013-01-01

    Full Text Available This paper gives a novel explanation of the integral equation of Abel’s type from the point of view of Mikusinski’s operational calculus. The concept of the inverse of Mikusinski’s operator of fractional order is introduced for constructing a representation of the solution to the integral equation of Abel’s type. The proof of the existence of the inverse of the fractional Mikusinski operator is presented, providing an alternative method of treating the integral equation of Abel’s type.

  2. Magmatic constraints on localization of natural stone deposits in the Vehmaa rapakivi granite batholith, southwestern Finland

    Directory of Open Access Journals (Sweden)

    Olavi Selonen

    2011-08-01

    Full Text Available The 1580–1570 Ma old Vehmaa rapakivi granite batholith was studied with the aim to define the geological constraints for localization of natural stone deposits in the batholith. The batholith comprises four roughly concentric granite intrusions from the margin inwards: pyterlite, coarse-grained porphyritic rapakivi granite and two types of medium-grained porphyritic rapakivi granite. Also porphyry aplite and even-grained rapakivi granite occur. The batholith has intruded as a succession of pulses of subhorizontal sheet-like intrusions conceivably through repeated cauldron subsidence. Natural stone quarries are confined only to certain intrusions within the batholith. We show that the medium-grained porphyritic granite body in the centre of the batholith comprises two almost identical but different intrusions, with only slightly different appearances: the inner (IG and the outer (OG granite. The quarries are confined to the outer intrusion which has an appearance more attractive to the market than that of the inner intrusion. The localization of the natural stone deposits in the Vehmaa batholith is a result of the magmatic history of the batholith, producing intrusions of different appearances with different commercial potential.

  3. Contribution of Portuguese two-mica granites to stone built heritage

    Science.gov (United States)

    Almeida, Angela; Begonha, Arlindo

    2013-04-01

    The present study deals with the importance of the application of natural stone in monuments in urban setting, both as the main building material during the historical evolution of a city and as a means to increase the public awareness of the social role of geological resources of a specific region. The City of Oporto, World Heritage of the Humanity , has been selected to illustrate the use of the local granite since ancient times to the present day, a two-mica peraluminous granite ,classified as syn-tectonic relatively to the third tectonic deformation phase of the Hercynian orogeny, included in an expressive group that occurs extensively in northern Portugal . The Oporto granite has been the object of several geochemical, structural and geotechnical approaches. Despite the urban development, outcrops of this granite can be observed in different areas of the city, side by side with the urban constructions, and particularly in the imposing and intensely fractured escarpments carved by the river Douro. Oporto monumental heritage goes back to Roman occupation and the profile has been developed by the construction of granite buildings, following history and the social evolution, of an impressive grey architecture according to different styles of granite work that characterize the city in all its aspects, namely the old city wall, the medieval and baroque churches, the neoclassic houses but also the small humble habitations. The Oporto granite is always affected by weathering processes and the buildings exhibit various aspects of stone decay such as granular desintegration, plates, flakes, black crusts, thin black layers, efflorescences and biological colonization. The description of selected sites within the historical centre , where it is possible to recognize the importance of the granite in the character of the city, aims to call the attention to the inextricable role of geology in built heritage and in the culture, as well as to diagnose the deterioration

  4. Mineralogy, geochemistry, and petrology of Neoarchean ferroan to magnesian granites of Carajás Province, Amazonian Craton: The origin of hydrated granites associated with charnockites

    Science.gov (United States)

    Dall'Agnol, Roberto; Cunha, Ingrid Roberta Viana da; Guimarães, Fabriciana Vieira; Oliveira, Davis Carvalho de; Teixeira, Mayara Fraeda Barbosa; Feio, Gilmara Regina Lima; Lamarão, Claudio Nery

    2017-04-01

    2.75 to 2.73 Ga old granitic intrusions associated with coeval charnockitic rocks were emplaced in the northern domains of the Carajás Province. The Vila Jussara Suite was recognized recently and its geologic, mineralogical and geochemical characteristics are presented in this paper and compared with the data available in the literature on the Estrela Complex, Serra do Rabo and Igarapé Gelado granites and Planalto Suite. Monzogranites and syenogranites are dominant in most units but in the Igarapé Gelado Granite and Vila Jussara Suite granodiorites and tonalites are also relatively abundant. The main mafic phases in all these granitoids are amphibole [potassian hastingsite with subordinate magnesiohastingsite; 0.95 ≥ Fe/(Fe + Mg) ≥ 0.47] and biotite [0.88 ≥ Fe/(Fe + Mg) ≥ 0.52] with rare occurrence of clinopyroxene relict crystals. Magmatic epidote (% of 'pistacite' component from 26 to 31) occurs only in the Vila Jussara Suite. The rocks of Estrela, Serra do Rabo, and Planalto units contain only ilmenite generally with coronas of titanite or ilmenite associated with magnetite and are essentially reduced-ferroan granites [whole rock FeOt/(FeOt + MgO) ≥ 0.89] that evolved at low fO2 (FMQ ± 0.5). The Igarapé Gelado Granite needs additional studies but it is formed apparently by reduced-ferroan and oxidized-ferroan granites. The Vila Jussara Suite is also composed of reduced-ferroan granites that are similar to those of the other granite units. However, it has additionally oxidized-ferroan and magnesian granitoids which contain magnetite (± ilmenite) as the main Fe-Ti oxide phase and evolved, respectively, at moderate fO2 (NNO ± 0.5) and at comparatively higher fO2 (NNO to NNO + 1). The magmas of these granites were formed at temperatures ≥ 900°C and derived from a heterogeneous dominantly reduced and tholeiitic granulitic crust locally varying to oxidized and calc-alkaline in composition. Plagioclase, orthopyroxene, clinopyroxene and Fe-Ti oxides

  5. A Record of Magmatic and Hydrothermal Fluids in the Irish Crust: Evidence from Caledonian Granites

    Science.gov (United States)

    Conliffe, J.; Feely, M.

    2006-05-01

    Fluid inclusions studies of granite quartz can provide evidence for major syn and post emplacement fluid influxes in and around granite bodies. Late Caledonian granites form a major component of the Irish crust, and facilitate the study of major hydrothermal fluid trapping events within the crust. We report the results of a regional scale fluid inclusion study of late Caledonian granite quartz. A variety of fluid signatures have been recorded, including evidence of magmatic, meteoric and low-temperature fluid influxes during evolution of the Irish crust over the past 400 Ma. Three main fluid inclusion types have been recognised in granite quartz. The earliest fluid type identified is a H2O-CO2-NaCl ± CH4 fluid, with high homogenisation temperatures (~300-450°C) and moderate salinities (3-16 eq. wt% NaCl). These inclusions display characteristic of primary fluid inclusions and their origin remains enigmatic. However the presence of these inclusions is restricted to granite bodies originating from subduction related melts, or lower crustal melts. Evidence for a later influx of H2O-NaCl-KCl fluids is preserved in all granites. Stable isotope analysis has identified this fluid as being meteoric in origin, and linked this fluid to the widespread retrograde alteration observed in some of these granite bodies. Finally a H2O-NaCl-CaCl2 fluid has been recorded in some Caledonian granites. This fluid displays variable salinity (8-28 eq. wt% NaCl) and homogenisation temperatures (125-205°C, and reflects the late penetration of basinal brines into the granites after their final crystallisation. These fluids are similar to CaCl2-bearing waters associated with major Pb-Zn deposits hosted within the Carboniferous limestones of the Irish midlands. Genetic models for the formation of these deposits involve the circulation of these fluids within the Caledonian basement rocks, and it is believed the presence of these fluids is recorded within the Caledonian granites. The presence

  6. Tectonic significance of dikes of Westerly Granite, southeastern Connecticut and southwestern Rhode Island

    Science.gov (United States)

    Goldsmith, R.

    1988-01-01

    Undeformed Early Permian Westerly Granite dikes cut gneisses of the southeastern New England Avalon zone along coastal southeastern Connecticut and adjacent Rhode Island. Most dikes dip southward at a low angle. The Westerly dikes were emplaced in relatively warm rock penecontemporaneously with the Narragansett Pier Granite during a narrow time interval shortly after cessation of pervasive Alleghanian ductile deformation but probably before final localized movement on major shear zones. The gentle dips indicate subhorizontal release at the end stage of the Alleghanian compressive event. Doming, intrusion of granite, and subsequent rapid uplift and cooling are attributed to the underplating of Avalonian crust by an African plate during the Alleghanian. -Author

  7. A 3D Magnetotelluric Perspective on the Galway Granite, Western Ireland

    Science.gov (United States)

    Farrell, Thomas; Muller, Mark; Vozar, Jan; Feely, Martin; Hogg, Colin

    2017-04-01

    Magnetotelluric (MT) and audi-magnetotelluric (AMT) data were acquired at 75 locations across the exposed calc-alkaline Caledonian Galway granite batholith and surrounding country rocks into which the granite intruded. The Galway granite is located in western Ireland on the north shore of Galway bay, and has an ESE-WNW long axis. The granite is cut by trans-batholith faults, the Shannawona Fault Zone (SFZ) in the western part of the batholith, which has a NE-SW trend, and the Bearna Fault Zone (BFZ) in the eastern sector that has a NW-SE trend. Geobarometry data indicate that the central granite block between these fault zones has been uplifted, with the interpretation being that the granite in this central block is thinned. To the west of the SFZ, much of the Galway granite is below sea level, with the majority of the southern granite contact also beneath the sea in Galway bay. To the east of the batholith, the Carboniferous successions, consisting of mainly limestone with shale, overlie the basement rocks. The country rock to the north includes the metagabbro-gneiss suite, which itself intruded the deformed Dalradian successions that were deposited on the Laurentian margin of the Iapetus Ocean. The deformation of the Dalradian rocks, the intrusion of the metagabbro-gneiss suite and the intrusion of the Galway granite were major events in the protracted closure of the Iapetus Ocean. It is clear from geological mapping, from geobarometry and from the present submergence by the sea of a large part of the Galway granite, that inversion of MT data in this structurally complex geology is likely to require a 3D approach. We present a summary of 3D inversion of the Galway MT and AMT data. The study shows that the structure of the Galway granite is quite different from the pre-existing perspective. The central block, thought by its uplifting to be thinned, is shown to be the thickest part of the batholith. A geological model of granite intrusion is offered to explain this

  8. Mantle hydrous-fluid interaction with Archaean granite.

    Science.gov (United States)

    Słaby, E.; Martin, H.; Hamada, M.; Śmigielski, M.; Domonik, A.; Götze, J.; Hoefs, J.; Hałas, S.; Simon, K.; Devidal, J.-L.; Moyen, J.-F.; Jayananda, M.

    2012-04-01

    Water content/species in alkali feldspars from late Archaean Closepet igneous bodies as well as growth and re-growth textures, trace element and oxygen isotope composition have been studied (Słaby et al., 2011). Both processes growth and re-growth are deterministic, however they differ showing increasing persistency in element behaviour during interaction with fluids. The re-growth process fertilized domains and didn't change their oxygen-isotope signature. Water speciation showed persistent behaviour during heating at least up to 600oC. Carbonate crystals with mantle isotope signature are associated with the recrystallized feldspar domains. Fluid-affected domains in apatite provide evidence of halide exchange. The data testify that the observed recrystallization was a high-temperature reaction with fertilized, halide-rich H2O-CO2 mantle-derived fluids of high water activity. A wet mantle being able to generate hydrous plumes, which appear to be hotter during the Archean in comparison to the present time is supposed by Shimizu et al. (2001). Usually hot fluids, which can be strongly carbonic, precede asthenospheric mantle upwelling. They are supposed to be parental to most recognized compositions, which can be derived by their immiscible separation into saline aqueous-silicic and carbonatitic members (Klein-BenDavid et al., 2007). The aqueous fractions are halogen-rich with a significant proportion of CO2. Both admixed fractions are supposed to be fertile. The Closepet granite emplaced in a major shear zone that delimitates two different terrains. Generally such shear zones, at many places, are supposed to be rooted deep into the mantle. The drain, that favoured and controlled magma ascent and emplacement, seemed to remain efficient after granite crystallization. In the southern part of the Closepet batholiths an evidence of intensive interaction of a lower crust fluid (of high CO2 activity) is provided by the extensive charnockitization of amphibolite facies (St

  9. Zoology Department, University of Cape Town

    African Journals Online (AJOL)

    LIMPET POPULATIONS. G.M. BRANCH. Zoology Department, University of Cape Town. ABSTRACT. Patella coneolor occurs on the east coast of South Africa and predominates in the baJanoid zone ..... digitalis moves up the shore and forms loose clusters, while A. scabra is solitary, has a fixed homing behaviour, and does ...

  10. Occurrence of ghost crabs eastemCape

    African Journals Online (AJOL)

    O. ryderi feeds largely on stranded Physalia (Berry pers. comm.) the remains of which have been found pulled deep into their burrows. Their main predators in the study area seem to be mongooses (Viverridae, probably Myonax pul- verulentius the Cape Grey mongoose and Cynictis pencil- lata the yellow mongoose) which ...

  11. THE EASTERN CAPE PROVINCE OF SOUTH AFRICA

    African Journals Online (AJOL)

    POT ENTIAL FOR CASSAVA PRODUCTION IN THE BATHURST RÉGION OF. THE EASTERN CAPE ... Cassava (Manihot escrtlenta) is a minor crop in South Africa that has had periodic rises in interest since it was first cultivated in the country. Interest .... Hardened tissue culture plants were used to establish this trial due to ...

  12. Hepatitis e virus: Western Cape, South Africa

    NARCIS (Netherlands)

    R.G. Madden (Richie); Wallace, S. (Sebastian); M. Sonderup; Korsman, S. (Stephen); Chivese, T. (Tawanda); Gavine, B. (Bronwyn); Edem, A. (Aniefiok); Govender, R. (Roxy); English, N. (Nathan); Kaiyamo, C. (Christy); Lutchman, O. (Odelia); A.A. Eijck (Annemiek); S.D. Pas (Suzan); Webb, G.W. (Glynn W); Palmer, J. (Joanne); Goddard, E. (Elizabeth); Wasserman, S. (Sean); H.R. Dalton (Harry); C.W. Spearman

    2016-01-01

    textabstractAIM To conduct a prospective assessment of anti-hepatitis E virus (HEV) IgG seroprevalence in the Western Cape Province of South Africa in conjunction with evaluating risk factors for exposure. METHODS Consenting participants attending clinics and wards of Groote Schuur, Red Cross

  13. Tuberculosis drug resistance in the Western Cape

    African Journals Online (AJOL)

    Objectives. Drug resistance is a serious problem in the treatment of tuberculosis and a threat to successful tuberculosis control programmes. Local health workers have expressed concern that the increasing tuberculosis epidemic in the Western Cape is partly attributable to drug resistance. The aim of this study was to ...

  14. The Cape Times's portrayal of school violence

    African Journals Online (AJOL)

    UVP

    2016-05-30

    May 30, 2016 ... The study highlights the negative consequences of school violence on teaching and learning and on ... riddled parts of the WC, the detrimental effects thereof on the regions cannot be denied. ... looking at the problem in the media, the Cape Times frequently conveys the message to the general public that.

  15. neonatal bacterial meningitis in Cape Town children

    African Journals Online (AJOL)

    with proven bacterial meningitis at all the hospitaJs in the. Cape Town ... children with haemophilus and pneumococcal meningitis were similar ..... treatment policies. The current treatment policy in most of the hospitals in the area is that meningococcal meningitis is treated for at least 7 days, while the other types are treated.

  16. Palaemon pacijicus (Stimpson) in eastern Cape tidal

    African Journals Online (AJOL)

    1984-09-25

    Sep 25, 1984 ... study of marine benthos, IBP Handbook 16: 197 - 279, (eds). Holme, N.A. & Mcintyre, A.D., Blackwell, Oxford. DAY, J.H. 1980. A guide to marine life on South African shores,. A.A. Balkema, Cape Town. EMMERSON, W.D. 1983. Tidal exchange of two decapod larvae. Palaemon pacijicus (Caridea) and ...

  17. RECURRENT CONVULSIONS IN CAPE TOWN CHILDREN*

    African Journals Online (AJOL)

    1970-11-03

    Nov 3, 1970 ... Child Health, Medical School, University of Cape Town studied and the length of time ... into the fire and often into water. I brought him to your .... well controlled. The convulsions of mentally retarded children proved most difficult to control and in 10% of cases control was never satisfactory. DISCUSSION.

  18. Yersinia enterocolitica in the Western Cape*

    African Journals Online (AJOL)

    Yersinia enterocolitica, serotype 3, phage type 9a, has been isolated for the first time in the Western Cape. Sera from 59 abattoir workers were investigated for the presence of 0 and H agglutinins. These were present in one sample, suggesting a past infection. Sera from 115 Nama-speaking adults of the Kuboes area.

  19. Red Capes, Red Herrings, and Red Flags.

    Science.gov (United States)

    Fiske, Donald W.

    The argument that the personality structures obtained from retrospective ratings reflect semantic similarity structures has been as provocative as a red cape in the bull ring. High congruence between those two kinds of structures seems well established. What is less clear is how and why those structures differ from that for immediate judgments of…

  20. Trauma care – the Eastern Cape story

    African Journals Online (AJOL)

    natural deaths in the Eastern Cape are worryingly higher than the national average, i.e. 11.6% v. 11% and 15.7% v. 10.2%, respectively. The values are in keeping with the higher levels of poverty in the province. ... The huge burden of disease, together with poor ... Prevention in South Africa: Developments and Challenges.

  1. Recovery of eastern Cape heathland after fire

    Directory of Open Access Journals (Sweden)

    A. M. F. G. Jacot Guillarmod

    1983-11-01

    Full Text Available In parts of the eastern Cape, fire is increasing in frequency and intensity in heathland, due mainly to the presence of adventive exotic tree species. These adventives also smother the indigenous vegetation under a dense canopy or with leaf litter. This heathland* flora requires a long period to reach its climax and under present conditions, this is rarely attained.

  2. The Cape Times's portrayal of school violence

    Directory of Open Access Journals (Sweden)

    Corene de Wet

    2016-05-01

    Full Text Available This study explores the Cape Times's portrayal of school violence in the Western Cape (WC, South Africa, reporting on findings from a qualitative content analysis of 41 news articles retrieved from the SA Media database. The findings shed light on the victims and their victimisation, the perpetrators, as well as the context of the violence, identifying gangsterism, as well as school administrative and community factors as the reasons for violence in WC schools. It is argued that school violence and gangsterism are inextricably linked to the Cape Flats in particular, and that the interaction of forms of inequality and oppression such as racism, class privilege and gender oppression are structural root causes for school violence in this area of the WC. The study highlights the negative consequences of school violence on teaching and learning and on the economy. It is concluded that even if the Cape Times paints an exaggerated and atypical picture of violence in the gang-riddled parts of the WC, the detrimental effects thereof on the regions cannot be denied. The study therefore recommends a holistic approach to addressing the structural root causes of school violence where it takes place in the WC.

  3. 76 FR 66082 - Cape Cod National Seashore, South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2011-10-25

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  4. 75 FR 63854 - Cape Cod National Seashore, South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2010-10-18

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  5. 77 FR 22611 - Cape Cod National Seashore Advisory Commission; Cape Cod National Seashore, South Wellfleet, MA

    Science.gov (United States)

    2012-04-16

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  6. 77 FR 9699 - Cape Cod National Seashore Advisory Commission; Cape Cod National Seashore, South Wellfleet, MA

    Science.gov (United States)

    2012-02-17

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  7. 76 FR 81965 - Cape Cod National Seashore Advisory Commission; Cape Cod National Seashore, South Wellfleet, MA

    Science.gov (United States)

    2011-12-29

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  8. 75 FR 34479 - Cape Cod National Seashore; South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2010-06-17

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  9. 76 FR 44606 - Cape Cod National Seashore; South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2011-07-26

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  10. 76 FR 18778 - Cape Cod National Seashore; South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2011-04-05

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  11. 75 FR 5622 - Cape Cod National Seashore, South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2010-02-03

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  12. 76 FR 8768 - Cape Cod National Seashore, South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2011-02-15

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  13. 75 FR 48990 - Cape Cod National Seashore; South Wellfleet, MA; Cape Cod National Seashore Advisory Commission

    Science.gov (United States)

    2010-08-12

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  14. 75 FR 20380 - Cape Cod National Seashore; South Wellfleet, Massachusetts; Cape Cod National Seashore Advisory...

    Science.gov (United States)

    2010-04-19

    ...Notice is hereby given in accordance with the Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770, 5 U.S.C. App 1, Section 10) of a meeting of the Cape Cod National Seashore Advisory Commission.

  15. Petrography and Physicomechanical Properties of Rocks from the Ambela Granitic Complex, NW Pakistan

    Science.gov (United States)

    Arif, Mohammad; Bukhari, S. Wajid Hanif; Muhammad, Noor; Sajid, Muhammad

    2013-01-01

    Petrography and physicomechanical properties of alkali granites, alkali quartz syenite, and nepheline syenite from Ambela, NW Pakistan, have been investigated. Whereas the alkali quartz syenite and most of the alkali granites are megaporphyritic, the nepheline syenite and some of the alkali granites are microporphyritic. Their phenocryst shape and size and abundance of groundmass are also different. The values of unconfined compressive strength (UCS) are the lowest and highest for megaporphyritic alkali granite and alkali quartz syenite, respectively. However, all the four rock types are moderately strong. Correspondingly, their specific gravity and water absorption values are within the permissible range for use as construction material. The UCS for the alkali quartz syenite is the highest, most probably because (i) it has roughly equal amounts of phenocryst and groundmass, (ii) it displays maximum size contrast between phenocryst and groundmass, (iii) its phenocrysts are highly irregular, and (iv) it contains substantial amounts of quartz. PMID:23861654

  16. LGR adult trap data - Operation of the adult trap at Lower Granite Dam

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Bonneville Power Administration (BPA) - funded project pays for NOAA staff to operate the adult salmon trap located in the fish ladder at Lower Granite Dam. The...

  17. Behavior of granite-epoxy composite beams subjected to mechanical vibrations

    Directory of Open Access Journals (Sweden)

    Antonio Piratelli-Filho

    2010-12-01

    Full Text Available The capacity to damp mechanical vibrations is one of the most important properties of granite-epoxy composites, even superior to the cast iron one. For this reason, these materials have been adopted for manufacturing of tool machine foundations and precision instruments. This work presents a study concerning the behavior of particulate composite beams, based on granite powder and epoxy, subjected to mechanical vibrations. Composite samples were prepared with different combinations of processing variables, like the weight fraction of epoxy in the mixture and size distributions of granite particles. The damping behavior of the material was investigated adopting the logarithmic decrement method. Samples, in the form of prismatic beams, were excited in the middle point and the output signal was measured in a point located at the extremity. The obtained results showed that composite samples, with weight fractions of about 80% of granite and 20% of epoxy, presented damping properties approximately three times greater than gray cast iron.

  18. Geochronology and thermobarometry of the granitoid rocks within the Vaasa granite-migmatite complex, western Finland

    Science.gov (United States)

    Kurhila, Matti; Kotilainen, Anna; Tiljander, Mia; Hölttä, Pentti; Korja, Annakaisa

    2015-04-01

    The Vaasa granite-migmatite dome in west-central Finland has been formed in the Svecofennian orogeny, after the main collisional stage at ~1.9 Ga. The structure consists of a granite-migmatite core surrounded by metasedimentary rocks with outward decreasing metamorphic grade. The core comprises anatectic garnet-bearing granites, diatexites, pyroxene granites, and minor intrusive granodiorites. Geochemically, all of the rocks are peraluminous and magnesian. The Vaasa granites have close to average upper crustal compositions, and they show signs of titanite and plagioclase fractionation. The heavy REEs vary strongly according to garnet retention. Zircon U-Pb ages for these rock types indicate crystallization at 1875 Ma for the diatexites and garnet-bearing granites and at 1870 Ma for the pyroxene granites. Melt-forming temperatures are estimated by zircon and monazite saturation temperatures, and by Al/Ti ratios. No clear difference in the melting temperatures of the various rock types could be detected. However, while the monazite and zircon saturation temperatures point to temperatures around 800 ° C, the Al-Ti thermometer gives consistently about 100 ° C degrees higher results. Given the anatectic and felsic nature of the rocks, the lower temperature estimates seem more probable. Crystallization temperatures and pressures were calculated with the help of mineral chemical analyses. Garnet-biotite-plagioclase-quartz thermobarometry, and Al-in-hornblende barometry indicate pressures of 5.5-6 kbars for the diatexites, the pyroxene granites and an intrusive granodiorite. Significantly lower pressures of 2-4 kbars are recorded for the garnet-bearing granites. The garnet-biotite thermometer implies crystallization temperatures between 650 - 700 ° C for the pyroxene granites and the diatexites, and upto 600 ° C for the garnet-bearing granites. These results are markedly lower than those indicated by the whole-rock saturation temperatures of the same rocks. This may

  19. A 'private adventure'? John Herschel's Cape voyage and the production of the 'Cape Results'

    Science.gov (United States)

    Ruskin, Steven William

    2002-07-01

    This dissertation considers the life of John Herschel (1792 1871) from the years 1833 to 1847. In 1833 Herschel sailed from London to Cape Town, southern Africa, to undertake (at his own expense) an astronomical exploration of the southern heavens, as well as a terrestrial exploration of the area around Cape Town. After his return to England in 1838, he was highly esteemed and became Britain's most recognized scientist. In 1847 his southern hemisphere astronomical observations were published as the Cape Results. The main argument of this dissertation is that Herschel's voyage, and the publication of the Cape Results, in addition to their contemporary scientific importance, were also significant for nineteenth-century politics and culture. This dissertation is a two-part dissertation. The first part is entitled “John Herschel's Cape Voyage: Private Science, Public Imagination, and the Ambitions of Empire”; and the second part, “The Production of the Cape Results.” In the first part it is demonstrated that the reason for Herschel's cultural renown was the popular notion that his voyage to the Cape was a project aligned with the imperial ambitions of the British government. By leaving England for one of its colonies, and pursuing there a significant scientific project, Herschel was seen in the same light as other British men of science who had also undertaken voyages of exploration and discovery. It is then demonstrated, in the second part of this work, that the production of the Cape Results, in part because of Herschel's status as Britain's scientific figurehead, was a significant political and cultural event. In addition to the narrow area of Herschel scholarship, this dissertation touches on other areas of research in the history of science as well: science and culture, science and empire, science and politics, and what has been called the “new” history of scientific books.

  20. Maternal mortality in the Cape Province, 1990 - 1992

    African Journals Online (AJOL)

    placentae or severe pre-eclampsia, involves decision- making in larger regional and tertiary hospitals. S Atr Med J 1996; 86: 412·418. ..... 18. 100. ·P=O.lS. Region. Total deliveries. Maternal deaths. Western Eastern Northern Eastern. Cape Cape (PE) Cape Cape (El.) P-value. Average age (yTs). 28.2. 29.2. 27.4. 24.1. 0.08.

  1. Permian ultrafelsic A-type granite from Besar Islands group, Johor ...

    Indian Academy of Sciences (India)

    This paper reports the occurrence of an A-type granite from peninsular Malaysia. The rocks occur in the Besar, Tengah, and Hujung islands located in the southeastern part of the peninsula. The granite is highly felsic with SiO2 ranging from 75.70% to 77.90% (differentiation index = 94.2–97.04). It is weakly peraluminous ...

  2. Modeling of lung cancer risk due to radon exhalation of granite stone in dwelling houses

    Directory of Open Access Journals (Sweden)

    Akbar Abbasi

    2017-01-01

    Conclusions: The estimated numbers of lung cancer deaths attributable to indoor radon due to granite stones in 2013 were 145 (3.33% and 103 (2.37% for poor and normal ventilation systems, respectively. According to our estimations, the values of 3.33% and 2.37% of lung cancer deaths in 2013 are attributed to radon exhalation of granite stones with poor and normal ventilation systems, respectively.

  3. METALLOGENY OF EOCENE SYNCOLLISIONAL GRANITES OF MOTAJICA AND PROSARA MOUNTAINS

    Directory of Open Access Journals (Sweden)

    Ivan Jurković

    2004-12-01

    Full Text Available The geological setting is dominated by Eocene (48.7 Ma syncollisional granitoids in the form of a small pluton in the Motajica Mt. and in the form of numerous sills and dykes in the Prosara Mt. Microelement paragenesis of these magmatites, pegmatites, greisens and quartz veins are distinguished by U, Th, Ce, Y, P, Nb, Ta, B, Li, F, Be, Sn, Mo, W, Fe, Cu, Pb. These elements and 87Sr/86Sr and 18O isotopic values indicate the mantle origin of magma contaminated by relatively sterile lithospheric rocks. The most probable hypothesis of such a hybrid magma formation is the "slab break-off model". Deep erosion of Motajica granitoid pluton opened its acrobatholitic and epibatholitic level with numerous, but small pegmatite deposits (beryllites, tourmalinites, emeraldites and sylexites with piezoelectric quartz. Greisenization marked by strong silicification and muscovitization affected less than 1% of pluton. It is characterized by minor and accessory molybdenite, wolframite, huebnerite, scheelite, fluorite. Hydrothermal occurrences, galena and Fe minerals have only a mineralogical significance. Economically significant are numerous autochthonous kaolin deposits formed in Pliocene-Pleistocene time. Prosara apomagmatic granitoids, exclusively granite dykes are metallogenetically sterile.

  4. Polishing Knowledge: A Study of Marble and Granite Processing

    Directory of Open Access Journals (Sweden)

    Simone De Bruim Babisk Mezadre

    2014-07-01

    Full Text Available The aim of this article is to understand the work situations and highlight aspects of the knowledge invested by workers when performing marble and granite processing activities. The survey is qualitative and was based on the reality of a small industrial company that deals with processing activities. The case study was based on theoretical and analytical ergology tools by analyzing the organizational documents and safety and health standards that regulate activity. It involved conducting individual interviews with nine workers, organizing a focus group with these workers, and directly observing work for four months while recording a field notebook. The workers’ experiences in the renormalization of working processes, or the introduction of improvements guided by singular aspects of the local work organization, were identified. The workers, through use of oneself, place more importance on meeting deadlines and production targets than on their own safety. Worker competency is directly related to the professional training obtained on the job and is associated with working experience in the absence of an a priori formal education. This article contributes to the field of organizational studies and human resource management because there is a lack of studies on workers from this field that describe the competencies used in actual work. Thus it may guide theoretical and practical management aspects in such working environments and small businesses regarding safer work organization.

  5. Cavity Radius Scaling for Chemical Explosions in Granite

    Science.gov (United States)

    Stroujkova, A. F.; Vorobiev, O.; Carnevale, M.

    2015-12-01

    It was long argued that the far-field seismic amplitudes from explosions are determined by the volume change in the source region, mainly due to a formation of the explosive cavities (e.g. Denny and Johnson, 1991). Weston Geophysical performed measurements of the cavities left by small chemical explosions in hard rock in New England. The comparison of the measured cavity sizes with historical data from nuclear and chemical explosions in hard rock (e.g. granite) shows that the cavity radii scale as W1/3 and appear to be depth independent because the rock strength significantly exceeds the overburden pressure for all possible explosion depths. The cavity sizes produced by nuclear explosions in softer rock (e.g. alluvium) deviate from the cubic root scaling and depend on the confining pressure. Cavity size calculations as a function of yield using hydrodynamic simulations with GEODYN, an Eulerian hydrodynamic code developed at Lawrence Livermore National Laboratory, support these observations. We investigate the effects of the cavity size as well as the extent of the damage zones on seismic radiation.

  6. ('tik') use among youth in the Western Cape, South Africa

    African Journals Online (AJOL)

    3 Department of Occupational Therapy, Faculty of Community and Health Sciences, University of the Western Cape, Cape Town, South Africa. 4 Bennett ... To identify (i) the prevalence of methamphetamine use in Western Cape youth and (ii) the association between use and known risk factors ... having a same-sex partner.

  7. Missed opportunities for immunisation in health facilities in Cape ...

    African Journals Online (AJOL)

    facilities in Cape Town, South Africa. N Jacob, MB ChB; D Coetzee, FCPHM. Western Cape Government: Health, and School of Public Health and Family Medicine, Faculty of Health Sciences, University of Cape Town, ..... Sudbury, MA: Jones & Bartlett, 2006. 5. Bernhardt GL, Cameron NA, Willems B, Boulle A, Coetzee D.

  8. The ABSA Cape Epic Mountain Bike Challenge: impacts and legacies

    African Journals Online (AJOL)

    The Absa Cape Epic mountain bike race is held in and around the mountainous areas outside Cape Town, in the Western Cape Province of South Africa, since 2004. The 700km-plus race, along farm roads and mountain tracks, extends over an eight day period. The race is limited to 600 two-person male and female teams, ...

  9. 33 CFR 117.823 - Cape Fear River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cape Fear River. 117.823 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.823 Cape Fear River. The draw of the Cape Fear Memorial Bridge, mile 26.8, at Wilmington need not open for the passage of vessel from 8...

  10. Sugar preferences and digestion by Cape white-eyes, Zosterops ...

    African Journals Online (AJOL)

    Sugar preferences and digestion by Cape white-eyes, Zosterops virens , fed artificial fruit diets. ... It appears likely that the Cape white-eye has high levels of sucrase activity, although further study is needed to verify this. Key words: frugivory, sugar, fruit composition, digestion, preference, Cape white-eye, Zosterops virens.

  11. Modeling and numerical analysis of granite rock specimen under mechanical loading and fire

    Directory of Open Access Journals (Sweden)

    Luc Leroy Ngueyep. Mambou

    2015-02-01

    Full Text Available The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton's second law, the rate-equation model of granite rock specimen under mechanical load and fire is established. The effect of heat treatment on the mechanical performance of granite is analyzed at the center and the ends of specimen. At the free end of granite rock specimen, it is shown that from 20 °C to 500 °C, the internal stress and internal strain are weak; whereas above 500 °C, they start to increase rapidly, announcing the imminent collapse. At the center of specimen, the analysis of the internal stress and internal strain reveals that the fire reduces the mechanical performance of granite significantly. Moreover, it is found that after 3 min of exposure to fire, the mechanical energy necessary to fragment the granite can be reduced up to 80%.

  12. ASSESSING LAND COVER CHANGES CAUSED BY GRANITE QUARRYING USING REMOTE SENSING

    Directory of Open Access Journals (Sweden)

    R. S. Moeletsi

    2017-11-01

    Full Text Available Dimension stone quarrying in the area between Rustenburg and Brits in the North West Province of South Africa has been in existence for over 70 decades. The unique characteristics of the granite deposits in South Africa resulted in making the country a global producer of the granite rocks. This led to intensified quarrying activities between Rustenburg and Brits town. However, this surface mining method, has a potential to impact the environment in a negative way causing loss in vegetation, depletion of natural resources, loss of scenic beauty and contamination of surface water resources. To assess the land cover changes caused by granite quarrying activities, remotely sensed data in the form of Landsat images between 1998 and 2015 were used. Supervised classification was used to create maps. Accuracy assessment using Google EarthTM as a reference data yielded an overall accuracy of 78 %. The post classification change detection method was used to assess land cover changes within the granite quarries. Granite quarries increased by 1174.86 ha while formation of quarry lakes increased to 5.3 ha over the 17-year period. Vegetation cover decreased by 1308 ha in area while 18.3 ha bare land was lost during the same period. This study demonstrated the utility of remote sensing to detect changes in land cover within granite quarries.

  13. Weathering-associated bacteria from the Damma glacier forefield: physiological capabilities and impact on granite dissolution.

    Science.gov (United States)

    Frey, Beat; Rieder, Stefan R; Brunner, Ivano; Plötze, Michael; Koetzsch, Stefan; Lapanje, Ales; Brandl, Helmut; Furrer, Gerhard

    2010-07-01

    Several bacterial strains isolated from granitic rock material in front of the Damma glacier (Central Swiss Alps) were shown (i) to grow in the presence of granite powder and a glucose-NH(4)Cl minimal medium without additional macro- or micronutrients and (ii) to produce weathering-associated agents. In particular, four bacterial isolates (one isolate each of Arthrobacter sp., Janthinobacterium sp., Leifsonia sp., and Polaromonas sp.) were weathering associated. In comparison to what was observed in abiotic experiments, the presence of these strains caused a significant increase of granite dissolution (as measured by the release of Fe, Ca, K, Mg, and Mn). These most promising weathering-associated bacterial species exhibited four main features rendering them more efficient in mineral dissolution than the other investigated isolates: (i) a major part of their bacterial cells was attached to the granite surfaces and not suspended in solution, (ii) they secreted the largest amounts of oxalic acid, (iii) they lowered the pH of the solution, and (iv) they formed significant amounts of HCN. As far as we know, this is the first report showing that the combined action of oxalic acid and HCN appears to be associated with enhanced elemental release from granite, in particular of Fe. This suggests that extensive microbial colonization of the granite surfaces could play a crucial role in the initial soil formation in previously glaciated mountain areas.

  14. The second continent: Existence of granitic continental materials around the bottom of the mantle transition zone

    Directory of Open Access Journals (Sweden)

    Kenji Kawai

    2013-01-01

    Full Text Available It has been thought that granitic crust, having been formed on the surface, must have survived through the Earth's evolution because of its buoyancy. At subduction zones continental crust is predominantly created by arc magmatism and is returned to the mantle via sediment subduction, subduction erosion, and continental subduction. Granitic rocks, the major constituent of the continental crust, are lighter than the mantle at depths shallower than 270 km, but we show here, based on first principles calculations, that beneath 270 km they have negative buoyancy compared to the surrounding material in the upper mantle and transition zone, and thus can be subducted in the depth range of 270–660 km. This suggests that there can be two reservoirs of granitic material in the Earth, one on the surface and the other at the base of the mantle transition zone (MTZ. The accumulated volume of subducted granitic material at the base of the MTZ might amount to about six times the present volume of the continental crust. Our calculations also show that the seismic velocities of granitic material in the depth range from 270 to 660 km are faster than those of the surrounding mantle. This could explain the anomalous seismic-wave velocities observed around 660 km depth. The observed seismic scatterers and reported splitting of the 660 km discontinuity could be due to jadeite dissociation, chemical discontinuities between granitic material and the surrounding mantle, or a combination thereof.

  15. Rapakivi Granite: An architectural emblem of St Petersburg and its utilisation in other world cities

    Science.gov (United States)

    Bulakh, Andrey; Gavrilenko, Vladimir; Panova, Helen

    2015-04-01

    The wide-ranging utilisation of Rapakivi Granite in St Petersburg is typified by the the famous Alexander Column, and 114 stone columns of St Isaac's Cathedralas well as the pedestal of the Nicholas I monument, and portals and basements of buildings of the Admiralty, General Staff, Senate and Synod. The stone is also frequently seen among pavement slabs and in parapets of embankments and bridges around the city. This list of examples where Rapakivi Granite has been used could be expanded further. All Rapakivi Granites used in the buildings of St.Petersburg were quarried from the so-called Vyborg massif. At present it has been found that the massif occupies an area of about 18 000 km2. In the past granite of the Vyborg massif was worked from several quarries in the vicinity of Fredrikshamn (Hamina) in Finland for use in St Peterburg. The best known granite quarries are at Piterlaks (Piuterlahti) and Gimmekyul (Hämeenkylä). Sometimes Rapakivi Granite form Finland differs in appearance from typical varieties. Thus columns of a classical portal in the house at N 7 in Pochtamtskaya Street are hewn from this greyish variety. Other examples are the plinth of the General Staff and Trade Store buildings. After the 1960s varieties from the Leningrad district, and Korosten (Ukraine) massifs were used in St Petersburg. Today it is possible to find examples of Rapakivi Granite from Finland in cities in the USA, South Africa, United Kingdom and Germany. It is a long used stone as demonstrated by its cultural heritage. It is also used as an ornamental or decorative stone in modern architecture. References: 1) Bulakh, A.G., Abakumova, N.B., and Romanovsky, J.V. St Petersburg: a History in Stone. 2010. Print House of St Petersburg State University. 173 p. (In English). 2) Tutakova, A.Ya., Romanovskiy, A.Z., Bulakh, A.G., and Leer, V.I. Dimension Stone of the Leningrad Region. Granites of the Karelia Isthmus in Architecture of the Modern St Petersburg. 2011. St Petersburg. 78 p

  16. Intracardiac thrombosis in the Cape Mountain Zebra

    Directory of Open Access Journals (Sweden)

    G.F. Bath

    1975-07-01

    Full Text Available The Cape mountain zebra (Equus zebra zebra is one of the rarest species of mammals in South Africa, and is threatened with extinction. At present there are less than 200 in existence, of which approximately 160 occur in the Mountain Zebra National Park near Cradock. Because of the rarity of the species and the undesirable concentration of the majority in an area of only 6 536 ha, a post-mortem examination is performed, if possible, on all animals to establish cause of death with the purpose of preventing large-scale mortalities. This is done even if the carcass is in a fairly advanced state of decomposition. Amongst the examinations so performed were two zebra which were believed to have died as a result of intraventricular thrombosis. The rarity of this condition and of the Cape mountain zebra makes a report on these cases necessary.

  17. [Analysis of X-ray fluorescence spectroscopy and plasma mass spectrometry of the Guidong granite body and its implications to granite evolution].

    Science.gov (United States)

    Li, Hong-Wei; Chen, Guo-Neng; Peng, Zhuo-Lun

    2013-07-01

    The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous. Analysis of the granites of different period with X-ray fluorescence spectroscopy and plasma mass spectrometry indicates: (1) From the top of a granite body downwards, the felsic components of rock decrease, while the mafic and sigmaREE, LREE/HREE, (La/Yb)N, as well as delta Eu value increase, suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB, the felsic compositions totally decrease, and the mafic components, sigmaEE, LREE/HREE, (La/Yb)N, and delta Eu value increase as well, implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting.

  18. The Cape Observatory: all Categories of Heritage

    Science.gov (United States)

    Glass, Ian S.

    2012-09-01

    In this presentation I will give an outline of the various types of heritage related to the Royal Observatory, Cape of Good Hope, established in 1820 and now the headquarters campus of the South African Astronomical Observatory, located quite close to downtown Cape Town. In terms of tangible, fixed heritage, the campus itself, the domes and the various other buildings are obviously relevant. This category includes the Classical Revival Main Building of 1828 and the McClean dome of 1895 by the leading colonial architect Herbert Baker as well as many other buildings and even the graves of two directors. Tangible movable items include, in principle, the telescopes, the accessory instruments and many pieces of apparatus that have been preserved. In addition, extensive collections of antique paintings, drawings, furniture and books add to the site's cultural significance. Many of the Observatory's archives are still kept locally. The intangible heritage of the Observatory consists for example of its history, its major discoveries, its interaction with the City, its central role in the history of science in South Africa and its appeal as a living cultural institution. Especially notable were the observations by Henderson (ca 1831) leading to the distance of a Cen and the early sky survey known as the Cape Photographic Durchmusterung.

  19. Alkali control of high-grade metamorphism and granitization

    Directory of Open Access Journals (Sweden)

    Oleg G. Safonov

    2014-09-01

    Full Text Available We review petrologic observations of reaction textures from high-grade rocks that suggest the passage of fluids with variable alkali activities. Development of these reaction textures is accompanied by regular compositional variations in plagioclase, pyroxenes, biotite, amphibole and garnet. The textures are interpreted in terms of exchange and net-transfer reactions controlled by the K and Na activities in the fluids. On the regional scale, these reactions operate in granitized, charnockitized, syenitized etc. shear zones within high-grade complexes. Thermodynamic calculations in simple chemical systems show that changes in mineral assemblages, including the transition from the hydrous to the anhydrous ones, may occur at constant pressure and temperature due only to variations in the H2O and the alkali activities. A simple procedure for estimating the activity of the two major alkali oxides, K2O and Na2O, is implemented in the TWQ software. Examples of calculations are presented for well-documented dehydration zones from South Africa, southern India, and Sri Lanka. The calculations have revealed two end-member regimes of alkalis during specific metamorphic processes: rock buffered, which is characteristic for the precursor rocks containing two feldspars, and fluid-buffered for the precursor rocks without K-feldspar. The observed reaction textures and the results of thermodynamic modeling are compared with the results of available experimental studies on the interaction of the alkali chloride and carbonate-bearing fluids with metamorphic rocks at mid-crustal conditions. The experiments show the complex effect of alkali activities in the fluid phase on the mineral assemblages. Both thermodynamic calculations and experiments closely reproduce paragenetic relations theoretically predicted by D.S. Korzhinskii in the 1940s.

  20. Contrasting Cu-Au and Sn-W Granite Metallogeny through the Zircon Geochemical and Isotopic Record

    Science.gov (United States)

    Gardiner, Nicholas; Hawkesworth, Chris; Robb, Laurence; Whitehouse, Martin; Roberts, Nick; Kirkland, Chris

    2017-04-01

    Magmatic genesis and evolution - mediated by geodynamic setting - exert a primary control on the propensity of granites to be metal fertile. A revolution in our understanding of these petrogenetic processes has been made through a range of mineral-based tools, most notably the common accessory mineral zircon. There is consequently considerable interest in whether the geochemical and isotopic compositions of zircon can be applied to metallogenic problems. The paired magmatic belts of Myanmar have broadly contrasting metallogenic affinities (Sn-W versus Cu-Au), and are interpreted to have formed on the accretionary margin of the subducting Neo-Tethys Ocean. They therefore present the opportunity to geochemically compare and contrast the zircon compositions in two end-member types of granite-hosted mineral deposits generated in collisional settings. We present an integrated zircon isotope (U-Pb, Lu-Hf, O) and trace element dataset that fingerprint: (a) source; (b) redox conditions; and (c) degree of fractionation. These variables all impact on magma fertility, and our key question to address is whether they can be reliably traced and calibrated within the Myanmar zircon record. Granitoid-hosted zircons from the I-type copper arc have juvenile ɛHf (+7 to +12) and mantle-like δ18O (5.3 ‰), whereas zircons from the S-type tin belt have low ɛHf (-7 to -13) and heavier δ18O (6.2-7.7 ‰). Plotting Hf versus U/Yb reaffirms that the tin belt magmas contain greater crustal contributions than the copper arc rocks. Links between whole rock Rb/Sr and zircon Eu/Eu* highlights that the latter can be used to monitor magma fractionation in systems that crystallize plagioclase (low Sr/Y). Ce/Ce* and Eu/Eu* in zircon are thus sensitive to redox and fractionation respectively, and can be used to evaluate the sensitivity of zircons to the metallogenic affinity of their host rocks. Tin contents that exceed the solubility limit are required in order to make a magmatic

  1. Granite disposal of U.S. high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Geoffrey A.; Mariner, Paul E.; Lee, Joon H.; Hardin, Ernest L.; Goldstein, Barry; Hansen, Francis D.; Price, Ronald H.; Lord, Anna Snider

    2011-08-01

    This report evaluates the feasibility of disposing U.S. high-level radioactive waste in granite several hundred meters below the surface of the earth. The U.S. has many granite formations with positive attributes for permanent disposal. Similar crystalline formations have been extensively studied by international programs, two of which, in Sweden and Finland, are the host rocks of submitted or imminent repository license applications. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in granite media. In this report we develop scoping performance analyses, based on the applicable features, events, and processes (FEPs) identified by international investigators, to support generic conclusions regarding post-closure safety. Unlike the safety analyses for disposal in salt, shale/clay, or deep boreholes, the safety analysis for a mined granite repository depends largely on waste package preservation. In crystalline rock, waste packages are preserved by the high mechanical stability of the excavations, the diffusive barrier of the buffer, and favorable chemical conditions. The buffer is preserved by low groundwater fluxes, favorable chemical conditions, backfill, and the rigid confines of the host rock. An added advantage of a mined granite repository is that waste packages would be fairly easy to retrieve, should retrievability be an important objective. The results of the safety analyses performed in this study are consistent with the results of comprehensive safety assessments performed for sites in Sweden, Finland, and Canada. They indicate that a granite repository would satisfy established safety criteria and suggest that a small number of FEPs would largely control the release and transport of radionuclides. In the event the U.S. decides to pursue a potential repository in granite, a detailed evaluation of these FEPs would be needed to inform site

  2. Jurassic high heat production granites associated with the Weddell Sea rift system, Antarctica

    Science.gov (United States)

    Leat, Philip T.; Jordan, Tom A.; Flowerdew, Michael J.; Riley, Teal R.; Ferraccioli, Fausto; Whitehouse, Martin J.

    2018-01-01

    The distribution of heat flow in Antarctic continental crust is critical to understanding continental tectonics, ice sheet growth and subglacial hydrology. We identify a group of High Heat Production granites, intruded into upper crustal Palaeozoic metasedimentary sequences, which may contribute to locally high heat flow beneath the West Antarctic Ice Sheet. Four of the granite plutons are exposed above ice sheet level at Pagano Nunatak, Pirrit Hills, Nash Hills and Whitmore Mountains. A new Usbnd Pb zircon age from Pirrit Hills of 178.0 ± 3.5 Ma confirms earlier Rbsbnd Sr and Usbnd Pb dating and that the granites were emplaced approximately coincident with the first stage of Gondwana break-up and the developing Weddell rift, and 5 m.y. after eruption of the Karoo-Ferrar large igneous province. Aerogeophysical data indicate that the plutons are distributed unevenly over 40,000 km2 with one intruded into the transtensional Pagano Shear Zone, while the others were emplaced within the more stable Ellsworth-Whitmore mountains continental block. The granites are weakly peraluminous A-types and have Th and U abundances up to 60.7 and 28.6 ppm respectively. Measured heat production of the granite samples is 2.96-9.06 μW/m3 (mean 5.35 W/m3), significantly higher than average upper continental crust and contemporaneous silicic rocks in the Antarctic Peninsula. Heat flow associated with the granite intrusions is predicted to be in the range 70-95 mW/m2 depending on the thickness of the high heat production granite layer and the regional heat flow value. Analysis of detrital zircon compositions and ages indicates that the high Th and U abundances are related to enrichment of the lower-mid crust that dates back to 200-299 Ma at the time of the formation of the Gondwanide fold belt and its post-orogenic collapse and extension.

  3. Intraplate seismicity across the Cape Verde swell

    Science.gov (United States)

    Vales, Dina; Matias, Luís.; Haberland, Christian; Silveira, Graça.; Weber, Michael; Carrilho, Fernando; Dias, Nuno

    2010-05-01

    The Cape Verde Archipelago ((15-17°N, 23-26°W) is located within the African plate, about 500km west of Senegal, in the African coast. The islands are located astride the Cape Verde mid-plate topographic swell, one of the largest features of its type in the world's ocean basins. The origin of this Cape Verde swell is still in debate. Previous determinations of the elastic thickness (Te) reveal a normal Te and a modest heat flow anomaly which suggest that the swell cannot be fully explained by uplift due to thermal reheating of the lithosphere by an underlying ‘‘hot spot'' and that other, deep-seated, mantle processes must be involved. The CV-PLUME (An investigation on the geometry and deep signature of the Cape Verde mantle plume) project intends to shape the geometry and deep origin of the Cape Verde mantle plume, via a combined study of seismic, magnetic, gravimetric and geochemical observations. Through this study we intend to characterize the structure beneath the archipelago from the surface down to the deep mantle. The core of this 3-year project was a temporary deployment of 39 Very Broad Band seismometers, across all the inhabited islands, to recorder local and teleseismic earthquakes. These instruments were operational from November 2007 to September 2008. In this work we report on the preliminary results obtained from the CV-PLUME network on the characterization of the local and regional seismicity. To detect the small magnitude seismic events the continuous data stream was screened using spectrograms. This proved to be a very robust technique in the face of the high short-period noise recorded by many of the stations, particularly during day time. The 10 month observation time showed that the background seismic activity in the Archipelago and surrounding area is low, with only a very few events recorded by the complete network. However, two clusters of earthquakes were detected close to the Brava Island, one to the NW and a second one, more active

  4. Mineralogy and mineral chemistry of rare-metal pegmatites at Abu Rusheid granitic gneisses, South Eastern Desert, Egypt

    National Research Council Canada - National Science Library

    Mohamed Fahmy Raslan; Mohamed A. Ali

    2011-01-01

    .... Correspondingly, mineralogical and geochemical investigation of pegmatites pockets scattered within Abu Rusheid granitic gneisses revealed the presence of Hf-zircon, ferrocolumbite and uranyl silicate minerals...

  5. Hydrothermal alteration and permeability changes in granitic intrusions related to Sn-W deposits : case study of Panasqueira (Portugal)

    Science.gov (United States)

    Launay, Gaetan; Sizaret, Stanislas; Guillou-Frottier, Laurent; Gloaguen, Eric; Melleton, Jérémie; Pichavant, Michel; Champallier, Rémi; Pinto, Filipe

    2017-04-01

    The Panasqueira Sn-W deposit occurs as a dense network of flat wolframite and cassiterite-bearing quartz veins concentrated in the vicinity of a hidden greisen cupola, and to a lesser extent as disseminated cassiterites in the greisen. Previous studies (Thadeu 1951; 1979) have suggested that the Panasqueira deposit is genetically related to magmatic activity for which the most part is unexposed, and being only represented by the greisen cupola. Hydrothermal fluid circulation during the final stages of granite crystallisation has probably led to the greisenisation of the cupola followed by the deposition of the mineralization in the veins system. Mineral replacement reactions that occurred during the greisenisation could affect rock properties (porosity, density and permeability) which control fluid circulation in the granite. This study aims to investigate effects of greisenisation reactions on the dynamic (time varying) permeability that ultimately leads to fluid circulation in the greisen cupola. To do so, petrological study and experimental determinations of hydrodynamic features (porosity and permeability) for different granite alteration levels and petrographic types (unaltered granite to greisen) are combined and then integrated in coupled numerical models of fluid circulation around the granitic intrusion. Greisen occurs in the apical part of the granitic body and results in the pervasive alteration of the granite along the granite-schist contact. This greisen consists mainly of quartz and muscovite formed by the replacement of feldspars and bleaching of biotites of the initial granite. Otherwise, greisen is generally vuggy which suggests a porosity increase of the granite during hydrothermal alteration processes. This porosity increase has a positive effect on the permeability of the granitic system. Indeed, experimental measurements of permeability with the Paterson press indicate that the initial granite is impermeable (10-20 m2) whereas the greisen is

  6. Evaluation of the effectiveness of laser crust removal on granites by means of hyperspectral imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pozo-Antonio, J.S., E-mail: santiago.pozo@udc.es [Laboratorio de Aplicacións Industriais do Láser, Centro de Investigacións Tecnolóxicas (CIT), Departamento de Enxeñaría Industrial II, Escola Politécnica Superior, Universidade de Coruña (UDC), Campus Ferrol, 15403 Ferrol (Spain); Fiorucci, M.P.; Ramil, A.; López, A.J. [Laboratorio de Aplicacións Industriais do Láser, Centro de Investigacións Tecnolóxicas (CIT), Departamento de Enxeñaría Industrial II, Escola Politécnica Superior, Universidade de Coruña (UDC), Campus Ferrol, 15403 Ferrol (Spain); Rivas, T. [Departamento de Enxeñaría dos Recursos Naturais e Medioambiente, Escola Superior de Minas, Universidade de Vigo, 36310 Vigo (Spain)

    2015-08-30

    Highlights: • Hyperspectral imaging techniques for determining the degree of crust removal on granites used in Cultural Heritage. • Hyperspectral imaging techniques allow to in situ evaluate of the effectiveness of the laser cleaning. • Hyperspectral imaging data are consistent with the information obtained by conventional techniques about the cleaning effectiveness. - Abstract: In this paper, we present a study of the application of the hyperspectral imaging technique in order to non-destructively evaluate the laser cleaning of the biogenic patina and the sulphated black crust developed on a fine-grained granite used in the construction of Cultural Heritage in NW Spain. The grained polymineral texture of the granite hinders the adjustment of laser irradiation parameters during the cleaning, and therefore the in situ process control. The cleaning was performed with a nanosecond pulsed Nd:YVO{sub 4} laser at 355 nm. A hyperspectral camera was used to in situ assess the effectiveness of cleaning by recording images of the rock surfaces before and during the laser treatment. Different analytical techniques were used to test the ability of the hyperspectral imaging technique to evaluate the cleaning process of the granite samples: optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM - EDX), Fourier transform infrared spectroscopy (FTIR) and spectrophotometer colour measurements. The results indicated that hyperspectral imaging technique is a reliable and more affordable technique to in situ evaluate the process of laser cleaning of the biogenic patina and the sulphated black crust in fine-grained granites.

  7. Three Paleoproterozoic A-type granite intrusions and associated dykes from Kainuu, East Finland

    Directory of Open Access Journals (Sweden)

    Hannu Huhma

    2010-12-01

    Full Text Available Mafic and felsic intrusive rocks aged 2.5–2.4 Ga have been observed over a large area in eastern and northern Finland, as well as in adjacent northwestern Russia. We describe three granite intrusions and associated dykes from Kainuu, Finland, that belong to this bimodal magmatic event. All these three granites show clear A2-type chemical affinities with high Y/Nb, HREE, Fe/Mg, Ga and Nb. Two of the intrusions, Rasinkylä and Pussisvaara, were dated at 2425±3 and 2427±3 Ma, respectively, using thermal ionisation mass spectrometry utilizing the chemical abrasion method (CA-TIMS. CA-TIMS ages are supported by single-grain age determinations obtained by using Laser Ablation Multicollector Inductively Coupled Plasma Mass Spectrometer (LA-MC-ICPMS. New data on the previously described Rasimäki granite from southern Kainuu is presented, including an age of 2389±5 Ma obtained with LA-MC-ICPMS. The variable magnetite content of the granites is proposed to reflect the differences in the oxidation state of the source, which in our interpretation is the local Archean lower crust. Partial melting and the emplacement of the granites occurred in an extensional environment. Heat for the partial melting was provided by mafic magmas under and intraplating the extended crust.

  8. High level and long life radioactive wastes. Todays situation and future evolutions. Framework and process of the Granite collegial mission of dialogue. FAQ about the Granite collegial mission of dialogue; Dechets radioactifs a haute activite et a vie longue. Situation actuelle et evolutions futures. Cadre et demarche de la mission collegiale de concertation Granite. Foire aux questions sur la mission collegiale de concertation Granite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    On December 9, 1998, the French government decided the construction of two underground laboratories for the study of the disposal of radioactive wastes in the deep underground. One site will be located in a granitic massif which remains to be determined. This document presents the framework and the different steps of the 'Granite' mission: the situation of radioactive wastes in France, some data about the conditioning, storage and reprocessing of high activity and long life radioactive wastes, the legal framework of the management of radioactive wastes and the related warranties, the disposal in deep underground and the realization of underground research laboratories, the government decision of December 9, 1998, the 'Granite' collegial mission of dialogue and the different steps of the geological surveys about granites. A second part answers some frequently asked questions about the 'Granite' collegial mission of dialogue: decision procedure, planning of the mission, consultation of the geologic survey, role of the mission, public information etc.. (J.S.)

  9. REE Comparison Between Muncung Granite Samples and their Weathering Products, Lingga Regency, Riau Islands

    Directory of Open Access Journals (Sweden)

    Ronaldo Irzon

    2016-11-01

    Full Text Available DOI:10.17014/ijog.3.3.149-161The increasing demand for Rare Earth Elements (REE is related to the continous development of technology, and these elements are used in modern equipments. REE can occur in igneous and sedimentary rocks in significant amounts as primary deposits, whereas the secondary REE deposit can be produced by intensive lateritic weathering of bedrocks under the tropical or subtropical climate. Lateritic process can increase REE concentration from sub-economic levels in host rocks to be more valuable. Muncung Granite is located in a tropical area of Lingga Regency, Riau Islands Province. REE occurs in the Muncung Granite and in weathered layers (saprolite, laterite, and soil. ICP-MS was applied to measure the REE content in all samples of this study. The average REE content of the Muncung Granite is 265 ppm with Eu anomaly in REE’s spider diagrams. Lateritization process has increased REE content by more than four times compared to that in the Muncung Granite. Ce and Eu anomalies in weathered layers can be associated with weathering process and initial REE contents in the host rock. Ce anomaly in a laterite layer is found to have a negative correlation to REE total enrichment. The REE level in the Muncung Granite is higher than the content in the soil and saprolite layers, but lower than that in the laterite.

  10. Three new species of Diascia (Scrophulariaceae from the Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    K. E. Steiner

    2009-12-01

    Full Text Available Three new annual species of Diascia Link & Otto are described from the Western Cape Province of South Africa. D. collina is characterized by greyish magenta flowers with two divergent yellow sacs containing oil-secreting trichomes. It is restricted to granite outcrops in the vicinity of Saldanha Bay, from the West Coast National Park and Langebaan north to Vredenburg. D. pusilla is closely related to D. collina. but differs from that species in having smaller flowers with shorter, ± parallel sacs, and posticous filaments that lack a protuberance where they bend sharply backwards towards the upper lip. It occurs in grey to whitish sands usually near seasonally moist or wet areas. It has not been found more than 35 km from the coast and ranges from Modderrivier, south o f Darling, north to Lambert’s Bay. D. appendiculata is related to D. diffusa (Thunb. Benth. and is characterized by having small, mainly reddish lilac to greyish magenta flowers, two shallow depressions in the corolla tube at the base of the upper lip, and posticous filaments with sterile appendages. It is known from only six localities in the general vicinity of Citrusdal and occurs in fynbos vegetation on lower mountain slopes or flats, in loose alluvial sands derived from Table Mountain Sandstone.

  11. TDP-43 stage, mixed pathologies, and clinical Alzheimer’s-type dementia

    Science.gov (United States)

    Wilson, Robert S.; Boyle, Patricia A.; Trojanowski, John Q.; Bennett, David A.; Schneider, Julie A.

    2016-01-01

    Hyperphosphorylated transactive response DNA-binding protein 43 (TDP-43, encoded by TARDBP) proteinopathy has recently been described in ageing and in association with cognitive impairment, especially in the context of Alzheimer’s disease pathology. To explore the role of mixed Alzheimer’s disease and TDP-43 pathologies in clinical Alzheimer’s-type dementia, we performed a comprehensive investigation of TDP-43, mixed pathologies, and clinical Alzheimer’s-type dementia in a large cohort of community-dwelling older subjects. We tested the hypotheses that TDP-43 with Alzheimer’s disease pathology is a common mixed pathology; is related to increased likelihood of expressing clinical Alzheimer’s-type dementia; and that TDP-43 pathologic stage is an important determinant of clinical Alzheimer’s-type dementia. Data came from 946 older adults with (n = 398) and without dementia (n = 548) from the Rush Memory and Aging Project and Religious Orders Study. TDP-43 proteinopathy (cytoplasmic inclusions) was present in 496 (52%) subjects, and the pattern of deposition was classified as stage 0 (none; 48%), stage 1 (amygdala; 18%), stage 2 (extension to hippocampus/entorhinal; 21%), or stage 3 (extension to neocortex; 14%). TDP-43 pathology combined with a pathologic diagnosis of Alzheimer’s disease was a common mixed pathology (37% of all participants), and the proportion of subjects with clinical Alzheimer’s-type dementia formerly labelled ‘pure pathologic diagnosis of Alzheimer’s disease’ was halved when TDP-43 was considered. In logistic regression models adjusted for age, sex, and education, TDP-43 pathology was associated with clinical Alzheimer’s-type dementia (odds ratio = 1.51, 95% confidence interval = 1.11, 2.05) independent of pathological Alzheimer’s disease (odds ratio = 4.30, 95% confidence interval = 3.08, 6.01) or other pathologies (infarcts, arteriolosclerosis, Lewy bodies, and hippocampal sclerosis). Mixed Alzheimer’s disease and

  12. Durability of fired clay bricks containing granite powder

    Directory of Open Access Journals (Sweden)

    Xavier, G. C.

    2012-06-01

    Full Text Available Over the past few decades, hundreds of papers have been published on the benefits of including rock powder as a raw material in fired clay brick manufacture. Very little has been written, however, about the durability and long-term behaviour of the final product. As a rule, the ceramic bricks used in construction in developing countries are fired at low temperatures, which detracts from their mechanical performance. This is particularly visible in harsh environmental conditions, where weathering causes severe deterioration. The present paper describes the impact of weathering on clay bricks containing from 0 to 10% granite powder, an industrial by-product. The specimens were fired at 500, 700 or 900 ºC and subsequently exposed to natural environmental conditions or accelerated laboratory weathering. Their physical and mechanical properties were evaluated to determine the effect of the composition of raw materials on fired clay product durability.

    En las últimas décadas se han publicado cientos de artículos sobre las ventajas de incluir polvo de roca como materia prima en la fabricación de los ladrillos cerámicos. Sin embargo, la durabilidad y el comportamiento a largo plazo del producto final han sido objeto de pocas investigaciones. Por lo general, los ladrillos cerámicos empleados en la construcción en los países en vías de desarrollo se cuecen a temperaturas bajas, lo que impide el desarrollo de sus propiedades mecánicas. Esto queda especialmente patente cuando las condiciones ambientales son severas, en cuyo caso la meteorización puede provocar un deterioro importante. En este artículo se describe el efecto de la meteorización en ladrillos cerámicos que incorporaban entre un 0 y un 10% de polvo de granito, que es un derivado industrial. Las probetas se cocieron a 500, 700 o 900 °C y luego se sometieron a condiciones ambientales naturales o a un proceso de laboratorio de meteorización acelerada. Se evaluaron sus

  13. Glacial modification of granite tors in the Cairngorms, Scotland

    Science.gov (United States)

    Hall, A.M.; Phillips, W.M.

    2006-01-01

    A range of evidence indicates that many granite tors in the Cairngorms have been modified by the flow of glacier ice during the Pleistocene. Comparisons with SW England and the use of a space-time transformation across 38 tor groups in the Cairngorms allow a model to be developed for progressive glacial modification. Tors with deeply etched surfaces and no, or limited, block removal imply an absence of significant glacial modification. The removal of superstructure and blocks, locally forming boulder trains, and the progressive reduction of tors to stumps and basal slabs represent the more advanced stages of modification. Recognition of some slabs as tor stumps from which glacial erosion has removed all superstructure allows the original distribution of tors to be reconstructed for large areas of the Cairngorms. Unmodified tors require covers of non-erosive, cold-based ice during all of the cold stages of the Middle and Late Pleistocene. Deformation beneath cold-based glacier ice is capable of the removal of blocks but advanced glacial modification requires former wet-based glacier ice. The depth of glacial erosion at former tor sites remains limited largely to the partial or total elimination of the upstanding tor form. Cosmogenic nuclide exposure ages (Phillips et al., 2006) together with data from weathering pit depths (Hall and Phillips, 2006), from the surfaces of tors and large erratic blocks require that the glacial entrainment of blocks from tors occurred in Marine Isotope Stages (MIS) 4-2, 6 and, probably, at least one earlier phase. The occurrence of glacially modified tors on or close to, the main summits of the Cairngorms requires full ice cover over the mountains during these Stages. Evidence from the Cairngorms indicates that tor morphology can be regarded as an important indicator of former ice cover in many formerly glaciated areas, particularly where other evidence of ice cover is sparse. Recognition of the glacial modification of tors is important

  14. Petrochemical evolution of the White Mfolozi Granite pluton: Evidence for a late Palaeoarchaean A-type granite from the SE Kaapvaal Craton, South Africa

    Science.gov (United States)

    Misra, Saumitra; Reinhardt, Jürgen; Wilson, Allan H.

    2017-08-01

    One of the major limitations in understanding the geochemical evolution of the Kaapvaal Craton, South Africa, is the scarcity of whole rock trace element data of the granitoid and other rocks compared to the vastness of this cratonic block. Here we present new XRF major oxide and ICP-MS trace element analyses of the White Mfolozi Granitoid (WMG) pluton, SE Kaapvaal Craton, which suggest that the 3.25 Ga (U-Pb zircon age) old WMG pluton is a peraluminous A-type granite and could be equivalent to the intrusive potassic granite phase of the Anhalt Granitoid suite, occurring to the North of the WMG pluton. The pluton was generated by batch partial melting of a pre-existing TTG source in two major phases under relatively anhydrous conditions, and the heat of partial melting could have been provided by a voluminous mantle-derived mafic magma, which intruded into mid-crustal levels (c. 17 km), perhaps during a period of crustal extension. The estimated pressure and temperature of generation of the WMG parent magma with average molar [or/(or + ab)] 0.48 could be 500 MPa and close to 1000 °C, respectively, when compared with the results of experimental petrology. Interstitial occurrence of relatively iron-rich biotite [Mg/(Mg + Fe) 0.41-0.45] suggests that the final temperature of crystallization of the pluton was close to 800 °C. An important magmatic event following the main phase of partial melting was limited mixing between the intrusive mafic magma and co-existing newly generated granitic melt. This magma mixing resulted in distinct variations in SiO2 and a low initial Sr isotopic ratio (0.7013) of the WMG pluton. Although both the models of partial melting of quartzo-feldspathic sources and fractional crystallization of basaltic magmas with or without crustal assimilation have been proposed for the origin of A-type granites, the model of magmatic evolution of the WMG pluton presented here can also be an alternative model for the generation of A-type granites. In

  15. Cape Hangklip area. II. The vegetation*

    Directory of Open Access Journals (Sweden)

    C. Boucher

    1978-12-01

    Full Text Available Various habitat factors influencing the fynbos vegetation of the Cape Hangklip area, such as topography, geology, soil and climate and historical features, are outlined. Data collected at 250 sampling sites are ordered using the Braun-Blanquet table method. The vegetation is subdivided into three main categories, namely coastal plain vegetation, mountain vegetation and riparian vegetation. A total of 29 communities is distinguished and related to habitat features. Aggressive introduced species which have become naturalized in the area, are also listed. A map showing the distribution of the plant communities is included.

  16. Some observations on two early Cape florilegia

    Directory of Open Access Journals (Sweden)

    E. G. H. Oliver

    1980-12-01

    Full Text Available A number of early Cape florilegia and codices exist in libraries in Europe and South Africa. Four of these florilegia are closely related and are housed in the Brenthurst Library, Johannesburg, the Botanical Research Institute, Pretoria, the Bodleian Library, Oxford and the Rijksherbarium, Leiden. The first two are compared and discussed in detail in this article. Arising from this comparison, a new interpretation of the interrelationship and origins of the four florilegia is proposed. The key volume is the florilegium in the Botanical Research Institute, Pretoria.

  17. Voluminous low-T granite: fluid present partial melting of the crust?

    Science.gov (United States)

    Hand, Martin; Barovich, Karin; Morrissey, Laura; Bockmann, Kiara; Kelsey, David; Williams, Megan

    2017-04-01

    Voluminous low-T granite: fluid present partial melting of the crust? Martin Hand(1), Karin Barovich(1), Laura Morrissey(1), Vicki Lau(1), Kiara Bockmann(1), David Kelsey(1), Megan Williams(1) (1) Department of Earth Sciences, University of Adelaide, Adelaide, Australia Two general schools of thought exist for the formation of granites from predominantly crustal sources. One is that large-scale anatexis occurs via fluid-absent partial melting. This essentially thermal argument is based on the reasonable premise that the lower crust is typically fluid depleted, and experimental evidence which indicates that fluid-absent partial melting can produce significant volumes of melt, creating compositionally depleted residua that many believe are recorded by granulite facies terranes. The other school of thought is that large-scale anatexis can occur via fluid-fluxed melting. This essentially compositional-based contention is also supported by experimental evidence which shows that fluid-fluxed melting is efficient, including at temperatures not much above the solidus. However, generating significant volumes of melt at low temperatures requires a large reservoir of fluid. If fluid-fluxed melting is a realistic model, the resultant granites should be comparatively low temperature compared to those derived from predominantly fluid-absent partial melting. Using a voluminous suite of aluminous granites in the Aileron Province in the North Australian Craton together with metasedimentary granulites as models for source behaviour, we evaluate fluid-absent verse fluid-present regimes for generating large volumes of crustally-derived melt. The central Aileron Province granites occupy 32,500km2, and in places are in excess of 8 km thick. They are characterised by abundant zircon inheritance that can be matched with metasedimentary successions in the region, suggesting they were derived in large part from melting of crust similar to that presently exposed. A notable feature of many of

  18. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    Science.gov (United States)

    Moura, Ana Catarina A; De Oliveira, Paulo H S; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Do Nascimento, Aderson F

    2014-12-01

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  19. A Study on Tribological Behavior of Glass-Epoxy Composite Filled with Granite Dust

    Science.gov (United States)

    Ray, Subhrajit; Rout, Arun Ku; KuSahoo, Ashok

    2017-08-01

    Granite powder is one of the solid wastes generated from stone processing industry used as organic filler replacing the conventional ceramic fillers in polymer matrix composite to increase the mechanical properties. The present work investigates the addition of granite powder on erosion wear properties of epoxy-glass fiber composite. The solid particle erosion wear rates of these hybrid composites are recorded considering various control parameters as impingement angles, erodent sizes and impact velocities following erosion resistance test in an air erosion test device at room temperatures. The test was conducted as per the Taguchi experimental design to minimize the erosion loss of material. The SEM views show the surface resistivity for the granite added specimens. The microscopic study also indicates various methods of material removal, crater wear and other subjective allocation during erosion experiment of the samples.

  20. Pioneering fungi from the Damma glacier forefield in the Swiss Alps can promote granite weathering.

    Science.gov (United States)

    Brunner, I; Plötze, M; Rieder, S; Zumsteg, A; Furrer, G; Frey, B

    2011-05-01

    Fungi were isolated from fine granitic sediments, which were collected at 15 sampling points within a 20 m × 40 m area in front of the Damma glacier in the central Swiss Alps. From the 45 fungal isolates grown on nutrient-rich agar media at 4 °C, 24 isolates were selected for partial sequencing and identification based on the small subunit ribosomal DNA. Sequencing data revealed that the isolated fungi represented three fungal phyla and 15 species. The weathering potential of 10 of the 15 fungal species was tested with dissolution experiments using powdered granite material (glacier forefield in which the fungi's capabilities to dissolve granite minerals were examined. © 2011 Blackwell Publishing Ltd.

  1. Effect of the state of internal boundaries on granite fracture nature under quasi-static compression

    Science.gov (United States)

    Damaskinskaya, E. E.; Panteleev, I. A.; Kadomtsev, A. G.; Naimark, O. B.

    2017-05-01

    Based on an analysis of the spatial distribution of hypocenters of acoustic emission signal sources and an analysis of the energy distributions of acoustic emission signals, the effect of the liquid phase and a weak electric field on the spatiotemporal nature of granite sample fracture is studied. Experiments on uniaxial compression of granite samples of natural moisture showed that the damage accumulation process is twostage: disperse accumulation of damages is followed by localized accumulation of damages in the formed macrofracture nucleus region. In energy distributions of acoustic emission signals, this transition is accompanied by a change in the distribution shape from exponential to power-law. Granite water saturation qualitatively changes the damage accumulation nature: the process is delocalized until macrofracture with the exponential energy distribution of acoustic emission signals. An exposure to a weak electric field results in a selective change in the damage accumulation nature in the sample volume.

  2. Comparative study of ornamental granite cleaning using femtosecond and nanosecond pulsed lasers

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, T., E-mail: trivas@uvigo.es [Dpto. Ingeniería de los Recursos Naturales y Medioambiente. E.T.S. Ingeniería de Minas, Universidad de Vigo, 36200 Vigo Spain (Spain); Lopez, A.J.; Ramil, A. [Centro de Investigaciones Tecnológicas. Campus de Esteiro. Universidad de A Coruña 15403 Ferrol Spain (Spain); Pozo, S. [Dpto. Ingeniería de los Recursos Naturales y Medioambiente. E.T.S. Ingeniería de Minas, Universidad de Vigo, 36200 Vigo Spain (Spain); Fiorucci, M.P. [Centro de Investigaciones Tecnológicas. Campus de Esteiro. Universidad de A Coruña 15403 Ferrol Spain (Spain); Silanes, M.E. López de [Dpto. Ingeniería de los Recursos Naturales y Medioambiente. E.I. Forestales. Universidad de Vigo, Campus Pontevedra. 36005 Pontevedra Spain (Spain); García, A.; Aldana, J. R. Vazquez de; Romero, C.; Moreno, P. [Grupo de Investigación en Microprocesado de Materiales con Laser. Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca Spain (Spain)

    2013-08-01

    Granite has been widely used as a structural and ornamental element in public works and buildings. In damp climates it is almost permanently humid and its exterior surfaces are consequently biologically colonized and blackened We describe a comparative analysis of the performance of two different laser sources in removing biological crusts from granite surfaces: nanosecond Nd:YVO{sub 4} laser (355 nm) and femtosecond Ti:Sapphire laser at its fundamental wavelength (790 nm) and second harmonic (395 nm). The granite surface was analyzed using scanning electron microscopy, attenuated total reflection – Fourier transform infrared spectroscopy and profilometry, in order to assess the degree of cleaning and to characterize possible morphological and chemical changes caused by the laser sources.

  3. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone

    Directory of Open Access Journals (Sweden)

    ANA CATARINA A. MOURA

    2014-12-01

    Full Text Available A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E–W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  4. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    Science.gov (United States)

    Moura, Ana Catarina A; Oliveira, Paulo H S DE; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Nascimento, Aderson F DO

    2014-10-24

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  5. "Gris Quintana": a Spanish granite from the Past into the Future.

    Science.gov (United States)

    José Tejado, Juan; Mota, M. Isabel; Pereira, Dolores

    2014-05-01

    "Gris Quintana" is a medium-grained, biotite and amphibole granodiorite extracted in the Pluton of Quintana de la Serena (Extremadura, Spain). It is a constant light grey granite from the Hercynian geologic with excellent physicomechanical and physicochemical properties. The granodiorite is composed of plagioclase, biotite, quartz and alkali feldspar, with accessory allanite, titanite, apatite, zircon and ilmenite, mostly as inclusions within the biotite crystals. This commercial variety is extracted from many quarries in the late Hercynian plutons located in the Iberian Massif in Spain period (transition between Central Iberian and Ossa-Moren Zones), having large reserves of granite. Many of the quarries have their own transformation factory (high production zone), with which the sector is offered an endless variety of finishes and constructive rock typologies. A wide range of solutions to architects and designers are offered. Gris Quintana granite is one of the materials with highest technological benefits that are used in arquitecture. "Gris Quintana" granite has been used since ancient times, not only at a regional, but also at national and international level: paving, building (structural, exterior façadas, interior uses), urban decoration and funeral art. It can be found in monuments and more recently, in buildings of different styles and uses, that stand out in beauty and splendor, lasting in time. Some singular works in "Gris Quintana" granite all over the world: extension to the "Congreso de Diputados" (Parliament) in Madrid, "Puerta de San Vicente" in Madrid, Andalucia Parliament columns in Sevilla, New Senate Buiding in Madird, "Gran Vía" pavement in Madrid, "Teatro Real façade" in Madrid… "Gris Quintana" granite accomplishes all the requirements for its nomination as Global Heritage Stone Resource, for both its use in construction and for artistic purposes.

  6. Sorption of Eu(III) on granite: EPMA, LA-ICP-MS, batch and modeling studies.

    Science.gov (United States)

    Fukushi, Keisuke; Hasegawa, Yusuke; Maeda, Koushi; Aoi, Yusuke; Tamura, Akihiro; Arai, Shoji; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi

    2013-11-19

    Eu(III) sorption on granite was assessed using combined microscopic and macroscopic approaches in neutral to acidic conditions where the mobility of Eu(III) is generally considered to be high. Polished thin sections of the granite were reacted with solutions containing 10 μM of Eu(III) and were analyzed using EPMA and LA-ICP-MS. On most of the biotite grains, Eu enrichment up to 6 wt % was observed. The Eu-enriched parts of biotite commonly lose K, which is the interlayer cation of biotite, indicating that the sorption mode of Eu(III) by the biotite is cation exchange in the interlayer. The distributions of Eu appeared along the original cracks of the biotite. Those occurrences indicate that the prior water-rock interaction along the cracks engendered modification of biotite to possess affinity to the Eu(III). Batch Eu(III) sorption experiments on granite and biotite powders were conducted as functions of pH, Eu(III) loading, and ionic strength. The macroscopic sorption behavior of biotite was consistent with that of granite. At pH > 4, there was little pH dependence but strong ionic strength dependence of Eu(III) sorption. At pH 4 was reproducible reasonably by the modeling considering single-site cation exchange reactions. The decrease of Eu(III) sorption at pH < 4 was explained by the occupation of exchangeable sites by dissolved cationic species such as Al and Fe from granite and biotite in low-pH conditions. Granites are complex mineral assemblages. However, the combined microscopic and macroscopic approaches revealed that elementary reactions by a single mineral phase can be representative of the bulk sorption reaction in complex mineral assemblages.

  7. Subsurface profiling of granite pluton using microtremor method: southern Aravalli, Gujarat, India

    Science.gov (United States)

    Joshi, Aditya U.; Sant, Dhananjay A.; Parvez, Imtiyaz A.; Rangarajan, Govindan; Limaye, Manoj A.; Mukherjee, Soumyajit; Charola, Mitesh J.; Bhatt, Meghnath N.; Mistry, Sagar P.

    2017-04-01

    We report, using the microtremor method, a subsurface granitic pluton underneath the Narukot Dome and in its western extension along a WNW profile, in proximity of eastern fringe of Cambay Rift, India. The dome and its extension is a part of the Champaner Group of rocks belonging to the Mesoproterozoic Aravalli Supergroup. The present finding elucidates development of an asymmetric double plunge along Narukot Dome. Microtremor measurements at 32 sites were carried out along the axial trace (N95°) of the dome. Fourier amplitude spectral studies were applied to obtain the ratio between the horizontal and vertical components of persisting Rayleigh waves as local ambient noise. Fundamental resonant frequencies with amplitude ≥1-sigma for each site are considered to distinguish rheological boundary. Two distinct rheological boundaries are identified based on frequency ranges determined in the terrain: (1) 0.2219-10.364 Hz recorded at 31 stations identified as the Champaner metasediment and granite boundary, and (2) 10.902-27.1119 Hz recorded at 22 stations identified as the phyllite and quartzite boundary. The proposed equation describing frequency-depth relationship between granite and overlaying regolith matches with those already published in the literature. The morphology of granite pluton highlights the rootless character of Champaner Group showing sharp discordance with granitic pluton. The findings of manifestation of pluton at a shallower depth imply a steep easterly plunge within the Champaner metasediments, whereas signature of pluton at a deeper level implies a gentle westerly plunge. The present method enables to assess how granite emplacement influences the surface structure.

  8. The in situ production of radioisotopes in rock matrices with particular reference to the Stripa granite

    Science.gov (United States)

    Andrews, J. N.; Davis, S. N.; Fabryka-Martin, J.; Fontes, J.-Ch.; Lehmann, B. E.; Loosli, H. H.; Michelot, J.-L.; Moser, H.; Smith, B.; Wolf, M.

    1989-08-01

    The in situ production of 3H, 14C, 36Cl, 129I, 37Ar, 39Ar, 81Kr and 85Kr by neutron-induced reactions and spontaneous nuclear decay processes has been estimated within the Stripa granite, its associated fracture minerals and surrounding leptite. Experimental measurements of the neutron flux within the Stripa granite are within 15% of theoretical values and have been used to calculate neutron-induced production rates. Activities of radionuclides that may enter groundwaters from the rock matrix are discussed in relation to their initial distribution in the host rock and their subsequent release into solution. The measured radioactivities in groundwaters from the high radioélément-content granites at Stripa are compared with estimates of their in situ production within the granite and of their solution by fracture-borne fluids. The activities of 3H and 14C which enter fracture fluids from the rock matrix are close to present detection limits. For 3H, the most significant production is within the rock matrix whilst for 14C it is within the circulating fracture fluids. Chlorine-36 production by neutron-capture within the granite is much more significant than inputs from cosmogenic and nuclear fallout sources. The 36Cl /Cl ratio may be used to evaluate Cl - sources in saline groundwaters. In situ production of 129I by spontaneous fission of 238U is an important source of 129I in the high radioactivity Stripa granite. Argon-37, 39Ar and 85Kr are produced by in situ reactions within the rock matrix, fracture mineralisation and at the sites of U-mineralisation, respectively. The use of some cosmogenic radionuclides for the estimation of groundwater residence times may be limited because of in situ production.

  9. Conventional U-Pb dating versus SHRIMP of the Santa Barbara Granite Massif, Rondonia, Brazil

    Science.gov (United States)

    Sparrenberger, I.; Bettencourt, Jorge S.; Tosdal, R.M.; Wooden, J.L.

    2002-01-01

    The Santa Ba??rbara Granite Massif is part of the Younger Granites of Rondo??nia (998 - 974 Ma) and is included in the Rondo??nia Tin Province (SW Amazonian Craton). It comprises three highly fractionated metaluminous to peraluminous within-plate A-type granite units emplaced in older medium-grade metamorphic rocks. Sn-mineralization is closely associated with the late-stage unit. U-Pb monazite conventional dating of the early-stage Serra do Cicero facies and late-stage Serra Azul facies yielded ages of 993 ?? 5 Ma and 989 ?? 13 Ma, respectively. Conventional multigrain U-Pb isotope analyses of zircon demonstrate isotopic disturbance (discordance) and the preservation of inherited older zircons of several different ages and thus yield little about the ages of Sn-granite magmatism. SHRIMP U-Pb ages for the Santa Ba??rbara facies association yielded a 207Pb/206Pb weighted-mean age of 978 ?? 13 Ma. The textural complexity of the zircon crystals of the Santa Ba??rbara facies association, the variable concentrations of U, Th and Pb, as well as the mixed inheritance of zircon populations are major obstacles to using conventional multigrain U-Pb isotopic analyses. Sm-Nd model ages and ??Nd (T) values reveal anomalous isotopic data, attesting to the complex isotopic behaviour within these highly fractionated granites. Thus, SHRIMP U-Pb zircon and conventional U-Pb monazite dating methods are the most appropriate to constrain the crystallization age of the Sn-bearing granite systems in the Rondo??nia Tin Province.

  10. A Search for Spectral Rotational Variations on S-Type Asteroids

    Science.gov (United States)

    Clark, B. E.; Rivkin, A. S.; Buie, M. W.

    1996-09-01

    We have initiated a statistical search for spectral rotational variations on S-type asteroids using the Ohio State Infrared Imaging Spectrometer (OSIRIS) at the 72 inch Perkins Telescope at Lowell Observatory. Spectral rotational variations may be the result of inherent mineralogic variations, or they may be the result of differential response to weathering across the surface of an asteroid. Previous studies of rotational variation have been plagued by instrumental inability to sample the spectrum quickly enough to prevent flux variations due to light curve variations or sky instability from showing up in the data. In addition, such studies have been limited to very few objects, and are usually constrained by brightness considerations (e.g. Gaffey 1984, Icarus 60). However, because spectra with OSIRIS are obtained simultaneously from 0.9 to 2.2 microns, we expect to have no such troublesome effects in the data, and OSIRIS will permit observations of asteroids at least as faint as 14th Vmag. Spectra have been obtained thus far for four S-type asteroids (20, 29, 126, 287) which have slow rotation rates and relatively low light-curve amplitudes. Each asteroid was observed on average three times spaced evenly over each of two nights. These data are part of an on-going effort to characterize the statistics of spectral rotational variability on S-type asteroids. A characterization of their occurrence will lead to better understanding of asteroid surface variations and their compositional interpretations.

  11. P-T path fluid evolution in the Gross Spitzkoppe granite stock, Namibia

    Directory of Open Access Journals (Sweden)

    Stephen Frindt

    2002-01-01

    Full Text Available The Gross Spitzkoppe granite stock (GSS is a zoned 30 km^2 epizonal intrusion that consists of three main granites: 1 medium-grained biotite granite (marginal, 2 a coarse-grained biotite granite, and 3 a central, porphyritic granite. The stock contains pegmatites as banded marginal stockscheiders and isolated pockets composed of large alkali feldspar and quartz, dark mica, interstitial fluorite, and euhedral topaz and beryl crystals. In the porphyritic granite there are local wolframite-bearing greisens and hydrothermal fluorite and topaz-rich veins.Fluid inclusion studies were conducted on: 1 topaz and quartz crystals from the marginal stockscheider; 2 quartz, topaz, fluorite and beryl crystals from isolated pegmatites; 3 topaz from a miarolitic pegmatite; 4 beryl and quartz veins from greisenized porphyritic granite; and 5 fluorite from a late fluorite vein inthe coarse-grained biotite granite. Preliminary data indicate the presence of three compositionally distinct primary and pseudosecondary inclusion types that are of late magmatic-hydrothermal origin.Type 1. Low salinity (0–10 eq. wt% NaCl H2O (± CO2 inclusions that homogenize to the liquid phase in the temperature range of 300 to 550˚C. These inclusions are from quartz, topaz and beryl. Inclusions in fluorite from the fluorite vein homogenize at ~170˚C and have a salinity of ca. 1–2 eq. wt% NaCl.Type 2. Saline (25–30 eq. wt% NaCl halite-bearing H2O (± CO2 inclusions that homogenize to the liquid phase in the temperature range of 300 to 400˚C. These inclusions are from quartz.Type 3. Low salinity (0–3 eq. wt% NaCl H2O-CO2 inclusions that homogenize to vapor phase in the temperature range of 330 to 550˚C. These inclusions are from quartz and topaz.Hydrothermal fluids from greisen minerals are represented by type 1 and type 2 H2O inclusions. They are predominantly of low salinity (~8 eq. wt% NaCl and homogenize to the liquid phase in the temperature range of 300 to 500

  12. Diffusivity of Sr, I and Pu in Granite With Through-Diffusion Experiment

    DEFF Research Database (Denmark)

    Dang, Hai-Jun; Hou, Xiaolin; Liu, Wen-yuan

    2014-01-01

    The diffusion behavior of Sr, I and Pu in granite was investigated by through-diffusion experiment. the effective diffusion coefficients of Sr, I and Pu in granite at 26 °C were determined to be (1.24±0.03)×10-13 m2/s, (2.88±0.02)×10-13 m2/s and (1.33±0.52)×10-13 m2/s, respectively. It is also ob...

  13. Sea Dredged Gravel versus Crushed Granite as Coarse Aggregate for Self Compacting Concrete in Aggressive Environment

    DEFF Research Database (Denmark)

    Sørensen, Eigil V.; Kristensen, Lasse Frølich

    2007-01-01

    Properties of self compacting concrete (SCC) with two types of coarse aggregate - sea dredged gravel with smooth and rounded particles and crushed granite with rough and angular particles - have been studied. Sea gravel allowed a higher aggregate proportion in the concrete leading to a higher...... modulus of elasticity. Tensile and compressive strength were found to depend both on aggregate type and on the properties of the interfacial zone close to the aggregate surface. Freeze-thaw scaling resistance was good with crushed granite, whereas sea gravel led to more severe scaling caused by porphyry...

  14. Drought Characteristics over the Western Cape Province, South Africa

    National Research Council Canada - National Science Library

    Christina M Botai; Joel O Botai; Jaco P de Wit; Katlego P Ncongwane; Abiodun M Adeola

    2017-01-01

    .... The present study assessed drought conditions using two categories of drought indicators computed from precipitation data sets measured by weather stations across the Western Cape Province, South...

  15. Blast! Cape Breton coal mine disasters

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, R.

    2007-07-01

    The book contains 18 chapters. Each chapter describes a major disaster (where three or more deaths occurred) in Cape Breton's coal mining history. The Lingan boiler explosion in 1877, the 1878 Sydney Mines explosion, 1892 Victoria Mines boiler explosions, No. 5 reserve gas explosion of 1903, runaway coal box at Scotia No. 4 in 1907, the 1908 Port Hood mine explosion, Florence No. 3 gas explosion in 1911, explosion at the New Waterford No. 12 Colliery in 1917, and a fall of stone at Inverness No.1 in 1924 are described. Other accidents were a runaway trip in 1937 and a runaway rake exactly a year later at the Sydney Mines Princess Colliery. A coal tank accident occurred at New Aberdeen No. 2 Colliery in 1943. Six disasters at Glace Bay are described: Caledonia fire and explosions in 1899, a boiler explosion at Numbers 2 and 9 surface plant in 1907, a speeding man rake in 1B Colliery in 1944, bump at No. 2 Colliery in 1946, and the explosions at No. 20 Colliery in 1952 and at No. 26 Colliery in 1979. A note containing a tribute to Cape Breton draegermen is included. 1 map.

  16. Pattern of elemental release during the granite dissolution can be changed by aerobic heterotrophic bacterial strains isolated from Damma Glacier (central Alps) deglaciated granite sand.

    Science.gov (United States)

    Lapanje, Aleš; Wimmersberger, Celine; Furrer, Gerhard; Brunner, Ivano; Frey, Beat

    2012-05-01

    Colonisation and weathering of freshly deglaciated granite are key processes in initial soil formation and development. We have obtained 438 isolates from granite sand covering glacial toe, 284 isolates at 22°C and 154 at 4°C incubation temperatures, respectively, to obtain cultures for the investigation of their weathering capabilities under laboratory conditions. The isolation of bacteria from granite sand was performed on rich-, intermediate- and low-nutrient-content solid media. Isolates were identified by 16S rRNA gene sequencing. According to the genera-associated weathering capabilities described in the literature and according to their abundance in our culture collection, we selected eight strains to analyse their effects on the weathering dynamics of granite sand during the batch culture experiment. Analysis of culturable bacteria showed higher species richness among isolates from 22°C than from 4°C incubations. In the R2A and 1/100 Ravan media, we observed the highest species richness of isolates obtained at 22°C and 4°C incubation temperatures, respectively. The obtained 16S rRNA sequences revealed the presence of alpha-, beta- and gamma-proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. The most numerous group of isolates was distantly related to Collimonas representatives, and according to the sequences of the 16S rRNA genes, they can form a new genus. Isolates from this group had the capability of causing increased dissolution rates for Fe, W, Ni and Rb. In general, at each sampling during the 30-day experiment, every strain showed a unique weathering profile resulting from differential rates of the dissolution and the precipitation of different minerals in the batch culture. Consequently, the presence of different strains, their growth stage and changes in proportions of strains in the bacterial community can affect further soil development and the successive colonisation by plants.

  17. Fluid paleocirculations at the cover/granite interface in the Rhine graben

    Science.gov (United States)

    Lerouge, Catherine; Dezayes, Chrystel; Bailly, Laurent; Flehoc, Christine; Guerrot, Catherine; Wille, Guillaume

    2017-04-01

    The Rhine Graben is a major site of development for the geothermal heating production in France. Targeted geothermal reservoirs are in deep Hercynian granitic basement which is fractured dominated system, and more recently at the cover/basement interface. In this framework of geothermal exploration, a better understanding of the hydraulic behaviour of the fracture network and fluid/rock interactions is needed. For that fracture fillings in Hercynian granitic basement and in the formations of the cover (Permian rhyolites, Permian and Triassic sediments) were studied for mineralogy, fluid inclusion microthermometry and (C, O, Sr) isotopes in order to trace paleocirculations at the cover/granite interface in the Rhine Graben. Data were acquired on fracture fillings in samples of the basement/cover interfaces from the EPS1 borehole at Soultz-sous-Forêt in the Rhine graben at 1417 meters depth, and from outcrops in quarries on the flanks of the graben (Waldhambach, Saint Pierre Bois, Windstein, Heidelberg). Mineral sequences of polyphased fillings were interpreted in relation with the geological context including late evolution of the Hercynian basement and major extensive tectonic events. Quartz, carbonates, sulfates and illite are major minerals identified in fractures crosscutting Hercynian granites, Permian rhyolite (Waldhambach) and Permian and Triassic sedimentary cover. Although quartz being considered as a major mineral filling fractures, petrological observations showed that carbonates are also an important and probably underestimated phase of filling, and of interest for two reasons. Firstly, from a geothermal point of view, they contribute to the clogging of fractures. Secondly, from a scientific point of view, they are informative on the variations of fluid chemistry through geological times. Among carbonates, dominant dolomite with minor ankerite, Mn-bearing carbonates and siderite was identified by CL, SEM and EPMA in fractures. A same generation of

  18. The Cape Town Statement on Geoethics

    Science.gov (United States)

    Di Capua, Giuseppe; Peppoloni, Silvia; Bobrowsky, Peter

    2017-04-01

    The interest of geoscientists in (geo)ethical aspects of geoscience knowledge, education, research and practice is rising and today geoethics has a significant visibility. This prominence is the result of hard work done in the last 4 years by the IAPG - International Association for Promoting Geoethics (http://www.geoethics.org), a not-for-profit, multidisciplinary, scientific network (with more than 1350 members in 107 countries) established for widening the discussion and creating awareness about problems of ethics applied to the geosciences. IAPG has produced a strong conceptual substratum on which to base the future development of geoethics, by clarifying the meaning of the word Geoethics, formalizing its definition, and identifying a framework of reference values on which the geoscience community can base more effective codes of conduct. IAPG members have published numerous books and articles in peer reviewed international journals, and organized scientific sessions to bring geoethics at the most important geoscience conferences. Geoethical issues have been included in the European project ENVRI-Plus, dedicated to the environmental and solid Earth research infrastructures. Moreover, the most prestigious geoscience organizations around the world now recognize geoethics as an important issue that warrants attention. This success was confirmed by the high quality of contents and the large participation of scientists in the 6 technical sessions and single panel session on geoethics organized by IAPG at the 35th IGC - International Geological Congress, held in 2016 in Cape Town (South Africa), with the cooperative work of different geoscience organizations (IUGS-TGGP - Task Group on Global Geoscience Professionalism; GSL - Geological Society of London; EFG - European Federation of Geologists; EGS - EuroGeoSurveys; AGI - American Geosciences Institute; AGU - American Geophysical Union, and AAWG - African Association of Women in Geosciences). IAPG considers the 35th

  19. Evaluation of the effectiveness of laser crust removal on granites by means of hyperspectral imaging techniques

    Science.gov (United States)

    Pozo-Antonio, J. S.; Fiorucci, M. P.; Ramil, A.; López, A. J.; Rivas, T.

    2015-08-01

    In this paper, we present a study of the application of the hyperspectral imaging technique in order to non-destructively evaluate the laser cleaning of the biogenic patina and the sulphated black crust developed on a fine-grained granite used in the construction of Cultural Heritage in NW Spain. The grained polymineral texture of the granite hinders the adjustment of laser irradiation parameters during the cleaning, and therefore the in situ process control. The cleaning was performed with a nanosecond pulsed Nd:YVO4 laser at 355 nm. A hyperspectral camera was used to in situ assess the effectiveness of cleaning by recording images of the rock surfaces before and during the laser treatment. Different analytical techniques were used to test the ability of the hyperspectral imaging technique to evaluate the cleaning process of the granite samples: optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM - EDX), Fourier transform infrared spectroscopy (FTIR) and spectrophotometer colour measurements. The results indicated that hyperspectral imaging technique is a reliable and more affordable technique to in situ evaluate the process of laser cleaning of the biogenic patina and the sulphated black crust in fine-grained granites.

  20. Impact of environmental dewatering of Lower Granite and Little Goose reservoirs on benthic invertebrates and macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Cushing, C.E.

    1993-09-01

    An investigation into the effects of dewatering on the benthic fauna in Lower Granite and Little Goose reservoirs was undertaken. Benthos in both the soft bottom regions of the reservoirs as well as those inhabiting the rock rip-rap along the shoreline were studied. These organisms provide an important food resource for both migrating salmonids and resident fish species; thus, impacts of contemplated dewatering schemes require evaluation. The results of these studies indicate that there were no significant, long-term impacts to the soft bottom benthos as a result of dewatering in Little Goose Reservoir. In fact, higher numbers of some taxa indicate that there may have been a washout of these organisms from Lower Granite Reservoir with subsequent deposition in the upper reaches of Little Goose Reservoir. This should be accompanied by a coincident decrease in these organisms in Lower Granite Reservoir. However, we did not have pre-dewatering samples from Lower Granite Reservoir with which we could compare post-filling samples to determine if the dewatering resulted in lower benthic populations.

  1. Influence de la structure des gneiss et des granites sur la resistance ...

    African Journals Online (AJOL)

    This paper presents a pattern of structure evaluation of gneiss and granite rocks from different areas of Togo and proposes a classification of these rocks based on their homogeneity and the regressions for the structures porphyroblastic, lepidoblastic and grainy. Finally the strength property, coefficient Los Angeles, ...

  2. Trace-element geochemistry of postorogenic granites from the northeastern Arabian Shield, Kingdom of Saudi Arabia

    Science.gov (United States)

    Stuckless, John S.; Knight, R.J.; VanTrump, G.; Budahn, J.R.

    1983-01-01

    Concentrations determined for all of the trace elements included in this study of postorogenic granites from the northeastern Arabian Shield are best described by log-normal distributions. The trace elements are divided into two groups: (1) compatible lithophile and siderophile elements (strontium, cobalt, scandium, manganese, europium, and titanium) and (2) incompatible lithophile elements (uranium, thorium, tantalum, rubidium, and rare-earth elements, except europium). The compatible elements exhibit greatest concentrations in the metaluminous postorogenic granites, and concentrations decrease with increasing degree of magma evolution. Economic potential for these elements and other geochemically similar elements is considered to be low. The concentrations of the incompatible elements increase with increasing degree of magma evolution and are greatest in the peralkaline and peraluminous granites. There is some geologic evidence that pegmatite and vein-forming processes were operative toward the end stage of postorogenic magmatism in the northeastern Arabian Shield, and therefore there is some probability for economic potential for these elements. It is suggested that such potential is greatest where highly evolved postorogenic granites intruded volatile (generally water )-rich country rocks.

  3. Dependency of hydromechanical properties of monzonitic granite on confining pressure and fluid pressure under compression

    Science.gov (United States)

    Wang, Huanling; Xu, Weiya; Lui, Zaobao; Chao, Zhiming; Meng, Qingxiang

    2016-05-01

    Monzonitic granite is a low-permeability rock. Monzonitic granite formations are ideal for underground storage of oil due to their low permeability and high mechanical strength. In this study, a series of coupled hydromechanical triaxial tests are carried out using monzonitic granite specimens. The influence of confining and fluid pressures on stress, strain, and permeability is investigated. Failure characteristics under different confining and fluid pressures are discussed based on the analysis of macro fracture planes and micro scanning electron microscopy (SEM). The test results show that the change of permeability with stress and strain reflects the deformation stages of compaction, compression, crack propagation, coalesce, and failure of cracks. Due to the low porosity, the change of permeability is small in the initial phases of compaction and compression, whereas there is a significant increase in permeability when new cracks start to develop and coalesce. Confining pressures have a significant impact on the strength and permeability, particularly the crack damage stress of the rock. Compared with confining pressure, the effect of fluid pressure on rock strength and crack damage stress is small. For the monzonitic granite specimens tested, changing the confining pressure results in different failure modes, whereas the fluid pressure has a relatively small effect on the failure modes.

  4. Geomechanical Studies on Granite Intrusions in Alxa Area for High-Level Radioactive Waste Disposal

    Directory of Open Access Journals (Sweden)

    Cheng Cheng

    2016-12-01

    Full Text Available Geological storage is an important concept for high-level radioactive waste (HLW disposal, and detailed studies are required to protect the environment from contamination by radionuclides. This paper presents a series of geomechanical studies on the site selection for HLW disposal in the Alxa area of China. Surface investigation in the field and RQD analyses on the drill cores are carried out to evaluate the rock mass quality. Laboratory uniaxial and triaxial compressive tests on the samples prepared from the drill cores are conducted to estimate the strength properties of the host rock. It is found that the NRG sub-area has massive granite intrusions, and NRG01 cored granite samples show the best rock quality and higher peak strength under various confinements (0–30 MPa. NRG01 granite samples are applied for more detailed laboratory studies considering the effects of strain rate and temperature. It is observed that the increasing strain rate from 1.0 × 10−5–0.6 × 10−2·s−1 can lead to a limited increase on peak strength, but a much more violent failure under uniaxial compressive tests on the NRG01 granite samples, and the temperature increasing from 20 °C–200 °C may result in a slight increase of UCS, as well as more ductile post-peak behavior in the triaxial compressive tests.

  5. Investigation on the Suitability of Fobur Granite in Jos, Plateau State ...

    African Journals Online (AJOL)

    The suitability of Fobur granite for road construction was investigated. Three samples A, B and C were handpicked from various locations on the quarry site using random sampling method. The samples were subjected to different tests namely chemical analysis, radioactivity, polishability, oxidization properties, porosity, ...

  6. Experimental Investigation of Crack Extension Patterns in Hydraulic Fracturing with Shale, Sandstone and Granite Cores

    Directory of Open Access Journals (Sweden)

    Jianming He

    2016-12-01

    Full Text Available Hydraulic fracturing is an important method of reservoir stimulation in the exploitation of geothermal resources, and conventional and unconventional oil and gas resources. In this article, hydraulic fracturing experiments with shale, sandstone cores (from southern Sichuan Basin, and granite cores (from Inner Mongolia were conducted to investigate the different hydraulic fracture extension patterns in these three reservoir rocks. The different reactions between reservoir lithology and pump pressure can be reflected by the pump pressure monitoring curves of hydraulic fracture experiments. An X-ray computer tomography (CT scanner was employed to obtain the spatial distribution of hydraulic fractures in fractured shale, sandstone, and granite cores. From the microscopic and macroscopic observation of hydraulic fractures, different extension patterns of the hydraulic fracture can be analyzed. In fractured sandstone, symmetrical hydraulic fracture morphology could be formed, while some micro cracks were also induced near the injection hole. Although the macroscopic cracks in fractured granite cores are barely observed by naked eye, the results of X-ray CT scanning obviously show the morphology of hydraulic fractures. It is indicated that the typical bedding planes well developed in shale formation play an important role in the propagation of hydraulic fractures in shale cores. The results also demonstrated that heterogeneity influenced the pathway of the hydraulic fracture in granite cores.

  7. Hercynian late-post-tectonic granitic rocks from the Fornos de Algodres area (Northern Central Portugal)

    Science.gov (United States)

    Azevedo, M. R.; Nolan, J.

    1998-10-01

    The Fornos de Algodres Complex (FAC) comprises several intrusions of late-post-tectonic Hercynian granitic rocks ranging in composition from hornblende granodiorites and quartz monzodiorites, through coarse porphyritic biotite granites and two-mica granites (coarse-, medium- and fine-grained), to muscovite-rich leucogranites. Field and regional constraints show that the emplacement of this large, composite, batholithic complex post-dates the main Variscan regional deformation phases (D 1+D 2+D 3) and associated metamorphic events. Field, petrographic and geochemical data suggest a strong genetic relationship between most of the members of the FAC. However, their Rb-Sr and Sm-Nd isotopic signatures appear to rule out any genetic process involving a single homogeneous source and/or closed-system fractional crystallization of the same parental magma. A model involving hybridization of mantle-derived basaltic liquids with crustal anatectic melts followed by further contamination and fractional crystallization is proposed to explain the isotopic and geochemical variation trends defined by the FAC granitic rocks.

  8. Aspects of the digestion in the Cape porcupine | van Jaarsveld ...

    African Journals Online (AJOL)

    The digestive capabilities of the Cape porcupine (Hystrix africaeaustralis) were studied using captive and field animals. The stomach contents comprised 6,47% of the body mass and had a low pH (2,0).The Cape porcupine also has a long small intestine (670 em). The large stomach and small intestine form a very efficient ...

  9. Some lexical aspects of Cape Muslim Afrikaans | Davids | Lexikos

    African Journals Online (AJOL)

    It is a relatively well known fact that Cape Muslim Afrikaans has its own distinctive pronunciations which at times differ sharply with that of Standard Afrikaans. What is not so well known, is that apart from its core vocabulary, which is derived from Dutch, Cape Muslim Afrikaans also has a distinctive lexical inventory, created to ...

  10. Arabic-Afrikaans Literature at the Cape | Dangor | Tydskrif vir ...

    African Journals Online (AJOL)

    To overcome this conundrum, numerous scholars and teachers began to translate Arabic texts into Cape Dutch and then transcribing these in the Latin script. These “readers” came to serve as official textbooks in the madrasahs at the Cape. This article traces the development of this genre of literature which came to be ...

  11. Changes in the Eastern Cape demersal inshore trawl fishery ...

    African Journals Online (AJOL)

    Changes in the Eastern Cape demersal inshore trawl fishery between 1967 and 1995. AJ Booth, T Hecht. Abstract. Changes in the Eastern Cape demersal inshore trawl fishery operating out of Port Elizabeth over a 28-year period from 1967 to 1995 are described. The fishery is restricted to vessels operating between ...

  12. Contributions to the biology of the Cape gurnard, Trigla capensis ...

    African Journals Online (AJOL)

    Contributions to the biology of the Cape gurnard, Trigla capensis (Pisces : Triglidae): age, growth and reproduction. T Hecht. Abstract. Study of otoliths of the Cape gurnard,Trigla capensis, has established that the rings are annular. An opaque zone is formed from February to Jury and a hyaline zone during the spawning ...

  13. Feeding ecology of major carnivorous fish from four eastern Cape ...

    African Journals Online (AJOL)

    1984-03-29

    Mar 29, 1984 ... Feeding ecology of major carnivorous fish from four eastern Cape estuaries. J.F.K. Marais. Department of Zoology, University of Port Elizabeth, Port Elizabeth. Stomach content analyses were performed on eight carnivorous fish from four eastem Cape estuaries. Dietary importance was assessed by using ...

  14. Comparison of nectar foraging efficiency in the Cape honeybee ...

    African Journals Online (AJOL)

    Colonies of African honeybees have significantly (p < 0,05) more unsuccessful foragers than colonies of Cape honeybees, while Cape colonies have significantly (p < 0,02) more foragers returning with nectar. No significant difference was observed in the numbers of returning pollen gatherers or foragers carrying both ...

  15. Territoriality of Cape Sugarbirds ( Promerops cafer ) between and ...

    African Journals Online (AJOL)

    Cape Sugarbirds are southern African endemics, found in fynbos vegetation of the Western and Eastern Cape Provinces of South Africa, and they feed almost exclusively on the nectar of Protea inflorescences. Breeding male Sugarbirds are highly territorial and defend resources for themselves, their mates and their ...

  16. Cephalopod diet of the Cape fur seal, Arctocephalus pusillus ...

    African Journals Online (AJOL)

    Scats of the Cape fur seal, Arctocephalus pusillus pusillus, were sampled at four mainland colonies, Cape Cross, Atlas Bay,Wolf Bay and Van Reenen Bay, along the Namibian coast over a period of eight years (1994–2001) to assess the diversity and spatial variability in the cephalopod component of the seal diet.

  17. Aspects of the digestion in the Cape porcupine

    African Journals Online (AJOL)

    Aspects of the digestion in the Cape porcupine. A.S. van Jaarsveld. Mammal Research Institute, University of Pretoria, Pretoria 0002. Republic of South Africa. The digestive capabilities of the Cape porcupine (Hystrix africaeaustralis) were studied using captive and field animals. The stomach contents comprised 6,47% of ...

  18. Short Note Lumbering the gauntlet: Cape Gannet fledglings killed by ...

    African Journals Online (AJOL)

    This account presents the first known observations of Cape Gannet Morus capensis fledgling mortalities as a result of aggressive nest defence behaviour by African Penguins Spheniscus demersus. Observations were conducted in 2013 on Bird Island, Algoa Bay, South Africa – the world's largest breeding colony of Cape ...

  19. Diet of Cape fur seals Arctocephalus pusillus pusillus at three ...

    African Journals Online (AJOL)

    In all, six main groups of teleost prey were identified, consisting of at least 48 species and 19 families. Cape Cross seals mainly consumed Cape horse mackerel Trachurus trachurus capensis, whereas lanternfish Lampanyctodes hectoris were negligible in their diet. At Van Reenen Bay and Atlas-Wolf Bay, the two southerly ...

  20. An audit of povincial Gastroenterology services in the Western Cape ...

    African Journals Online (AJOL)

    The aim of this study was to audit the availability of GI facilities in the provincial sector, which provides care for the majority of people in the Western Cape. Method. All hospitals in the Western Cape providing endoscopy were evaluated by means of a hands-on audit, to identify available organisational infrastructure.

  1. management of pulmonary tb in nurse-based cape town ...

    African Journals Online (AJOL)

    Kurt

    *1996 Census data, adjusted according to Dorrington (Table I derived from: Cape Town Metro Annual Reports on TB program — see 'Further reading'). Table II. Cape Town: Cure rates of new smear-positive TB cases (1997 - 2003). Cure rate. Success rate. Interruption rate. Failure rate. Death rate, all causes. 1997. 65. 74.

  2. The staff training and development initiatives at the Cape Peninsula ...

    African Journals Online (AJOL)

    Collaboration and partnerships between various stakeholders are crucial for the success and effectiveness of the implementation process, viz, university human resources learning and development (HR L&D) department, Cape Higher Education Consortium (CHEC), Cape Library Consortium (CALICO) and accredited ...

  3. Risk factors for meningococcal disease in Cape Town | Moodley ...

    African Journals Online (AJOL)

    To determine the risk factors associated with meningococcal disease among children living in Cape Town. Design. A case-control study was conducted from October 1993 to January 1995. Setting. The study population consisted of all children tmder the age of 14 years who were resident in the Cape Town metropolitan ...

  4. The "Cape Times"'s Portrayal of School Violence

    Science.gov (United States)

    de Wet, Corene

    2016-01-01

    This study explores the "Cape Times"'s portrayal of school violence in the Western Cape (WC), South Africa, reporting on findings from a qualitative content analysis of 41 news articles retrieved from the SA Media database. The findings shed light on the victims and their victimisation, the perpetrators, as well as the context of the…

  5. Child pedestrian injuries in the Cape metropolitan area - final results ...

    African Journals Online (AJOL)

    age presented to Red Cross War Memorial Children's _. Hospital in Cape Town having been injured as ... Trauma Unit and Department of Paediatric Surgery, Red Cross War. Memorial Children's Hospital, Cape Town .... residential streets in providing space for social interaction where the pedestrian should enjoy priority ...

  6. Rediscovery of the Cape warthog Phacochoerus aethiopicus : a ...

    African Journals Online (AJOL)

    ... of warthogs: the widespread common warthog Phacochoerus africanus and the Cape warthog P. aethiopicus. Whereas the Cape warthog, P. aethiopicus aethiopicus, became extinct in South Africa in the 1870s, it survives in Kenya, Ethiopia and Somalia as a geographically isolated subspecies, P. aethiopicus delamerei.

  7. Preschool development of coloured children in Cape Town ...

    African Journals Online (AJOL)

    Preschool development of coloured children in Cape Town. C.D. Molteno, J Hollingshead, A.D. Moodie, D Bradshaw, M.D. Bowie, W Willoughby. Abstract. Developmental screening was applied during infancy to a birth cohort of 1 000 coloured infants born consecutively in Cape Town. The developmental progress of a ...

  8. The Security and Development Nexus in Cape Town

    DEFF Research Database (Denmark)

    Jensen, Steffen Bo

    2010-01-01

    In this article, I argue that the security and development nexus takes on specific forms depending on the context, and that in Cape Town’s coloured townships it is embodied in policies and practices around what has come to be known as the ‘war on gangs’. Furthermore, the war on gangs in Cape Town...

  9. Facilities at ARIES for the Nainital–Cape Survey

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... A collaborative programme searching for mmag pulsations in chemically peculiar stars in the northern hemisphere was initiated in 1997 between Nainital, India, and Cape Town, South Africa. It was therefore named as the Nainital–Cape Survey programme. The detection limits imposed by the observing ...

  10. 33 CFR 117.829 - Northeast Cape Fear River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Northeast Cape Fear River. 117... Fear River. (a) The draw of the Isabel S. Holmes Bridge, at mile 1.0, at Wilmington, North Carolina... across the Cape Fear River. (2) The draw shall be left in the open position to vessels and will only be...

  11. Short Communications: First record of freshwater fish on the Cape ...

    African Journals Online (AJOL)

    During a non-exhaustive survey of freshwater bodies on five islands of the archipelago, the first presence of a freshwater fish was recorded. Using barcoding sequences, the species was identified as the guppy (Poecilia reticulata), a highly invasive species alien to the Cape Verdean Islands. Key words: Cape Verde, guppy, ...

  12. Cape Town's central city development: A strategy of partnership and ...

    African Journals Online (AJOL)

    In order to address this urban challenge, the Cape Town Partnership developed the Central City Development Strategy (CCDS), a ten-year plan that calls for the densification of the central city to re-plan Cape Town into a more liveable, inclusive, democratic, and sustainable urban space. By critically examining the role that ...

  13. Sexual behaviour of Cape Town high-school students | Flisher ...

    African Journals Online (AJOL)

    Objectives. To document prevalence rates for selected aspects of sexual behaviour among Cape Town high-school students and to conduct a survival analysis of age at first intercourse. Design. Cross-sectional survey. Setting. State high schools in Cape Town. Subjects. A multistage cluster sample of 2 740 grade 8 and 11 ...

  14. Surviving gangs, violence and racism in cape town

    DEFF Research Database (Denmark)

    Lindegaard, Marie Rosenkrantz

    Surviving Gangs, Violence and Racism in Cape Town offers an ethnographic study of young men in Cape Town and considers how they stay safe in when growing up in post-apartheid South Africa. Breaking away from previous studies looking at structural inequality and differences, this unique book focuses...

  15. High mite burdens in an island population of Cape Wagtails ...

    African Journals Online (AJOL)

    Cape Wagtails Motacilla capensis have been identified as a species susceptible to infection by the mite Knemidokoptes jamaicensis , but the processes influencing infection rates and prevalence have not been studied. We assessed the mite infection level of 117 Cape Wagtails captured during the 2005 breeding season on ...

  16. Comparison of nectar foraging efficiency in the Cape honeybee ...

    African Journals Online (AJOL)

    1987-03-17

    Mar 17, 1987 ... temperate races of honeybee. Studies on differences in colony metabolism and thermoregulation between south-western Cape and African honeybees ... lower energy expenditure than the African subspecies and this' adaptation is thought to enable the. Cape honeybee to survive the cold wet winters of the.

  17. The Cape Times's portrayal of school violence | de Wet | South ...

    African Journals Online (AJOL)

    This study explores the Cape Times's portrayal of school violence in the Western Cape (WC), South Africa, reporting on findings from a qualitative content analysis of 41 news articles retrieved from the SA Media database. The findings shed light on the victims and their victimisation, the perpetrators, as well as the context of ...

  18. Contrasting evolution of low-P rare metal granites from two different terranes in the Hoggar area, Algeria

    Science.gov (United States)

    Kesraoui, Mokrane; Nedjari, Samia

    2002-05-01

    Two mineralogically different rare metal granites located in two distinct terranes from the Tuareg area are compared: the Tin-Amzi granite in the north of the Laouni Terrane and the Ebelekan granite in the Assodé-Issalane Terrane. The Tin-Amzi granite is enclosed within Eburnean granulitic gneisses, and consists of albite, quartz, protolithionite, K-feldspar and topaz granite (PG). The accessory minerals include columbite tantalite, U- and Hf-rich zircon, Th-uraninite, wolframoixiolite and wolframite. This facies is characterised by a mineralogical evolution from the bottom to the top underlined by a strong resorption of K-feldspar and albite and the crystalliK-feldspar of more abundant topaz and protolithionite II which is further altered in muscovite and Mn-siderite. It is underlain by an albite, K-feldspar, F-rich topaz, quartz and muscovite granite (MG), with W-Nb-Ta oxides, wolframite, Nb-rutile, zircon and scarce uranothorite as accessories. The Ebelekan granite intrudes into a coarse-grained biotite granite enclosed within upper amphibolite-facies metasediments. It comprises a zinnwaldite, albite, topaz porphyritic granite (ZG) with "snow ball" quartz and K-feldspar. The accessories are zircon, monazite, uranothorite, Ta bearing cassiterite, columbite tantalite and wodginite. It is capped by a banded aplite-pegmatite (AP). The geochemistry of Tin-Amzi and Ebelekan granites is nearly comparable. Both are peraluminous (A/CNK=1.10-1.29; ASI=1.17-1.31), sodolithic and fluorine rich with high SiO 2, Al 2O 3, Na 2O+K 2O, Rb, Ga, Li, Ta, Nb, Sn and low FeO, MgO, TiO 2, Ba, Sr, Y, Zr and REE contents. These rare metal Ta bearing granites belong to the P-poor subclass, relating to their P 2O 5 content ( 0.03-0.15 wt.%). Nevertheless, they are distinguished by their concentration of W, Sn and Ta. The Tin-Amzi granite is W-Ta bearing with high W/Sn ratio whereas the Ebelekan granite is Ta-Sn bearing with insignificant W content. At Tin-Amzi the W-Nb-Ta minerals define

  19. Ultrasonic characterization of granites obtained from industrial quarries of Extremadura (Spain).

    Science.gov (United States)

    del Río, L M; López, F; Esteban, F J; Tejado, J J; Mota, M; González, I; San Emeterio, J L; Ramos, A

    2006-12-22

    The industry of ornamental rocks, such as granites, represents one of the most important industrial activities in the region of Extremadura, SW Spain. A detailed knowledge of the intrinsic properties of this natural stone and its environmental evolution is a required goal in order to fully characterize its quality. In this work, two independent NDT acoustic techniques have been used to measure the acoustic velocity of longitudinal waves in different prismatic granitic-samples of industrial quarries. A low-frequency transceiver set-up, based on a high-voltage BPV Steinkamp instrument and two 50 kHz probes, has been used to measure pulse travel times by ultrasonic through-transmission testing. In complementary fashion, an Erudite MK3 test equipment with an electromagnetic vibrator and two piezoelectric sensors has also been employed to measure ultrasonic velocity by means of a resonance-based method, using the same types of granite varieties. In addition, a comprehensive set of physical/mechanical properties have also been analyzed, according to Spanish regulations in force, by means of alternative methods including destructive techniques such as strength, porosity, absorption, etc. A large number of samples, representing the most important varieties of granites from quarries of Extremadura, have been analyzed using the above-mentioned procedures. Some results obtained by destructive techniques have been correlated with those found using ultrasonic techniques. Our experimental setting allowed a complementary characterization of granite samples and a thorough validation of the different techniques employed, thus providing the industry of ornamental rocks with a non-destructive tool that will facilitate a more detailed insight on the properties of the rocks under study.

  20. Geology and mineralogy of the Alakha spodumene granite porphyry deposit, Gorny Altai, Russia

    Science.gov (United States)

    Annikova, I. Yu.; Vladimirov, A. G.; Smirnov, S. Z.; Gavryushkina, O. A.

    2016-09-01

    The Alakha lithium-tantalum deposit in the southern Altai, Russia, is represented by a stock of spodumene-bearing granite porphyry localized in the Kalba-Narym-Koktogai lithium-tantalum rare-metal granitic belt, unique in extent (more than 1000 km). This belt is a part of the Altai accretionary-collisional system. Judging from forecasting, the Alakha deposit can be regarded as an uneroded proxy of a pegmatite body both in dimensions and mean Li2O and Ta2O5 contents (0.98 wt % and 114 ppm, respectively); however, the oregenerating potential of this deposit remains insufficiently studied and had not yet been claimed. In this paper, we attempt to fill this gap with a detailed mineralogical study, which allows us to provide insights into the crystallization of Li-bearing high-silicic magma and redistribution of components during magmatic and postmagmatic processes. Accessory mineral assemblages in muscovite-spodumene-K-feldspar granite porphyry and muscovite albitite—the main petrographic rock varieties of the Alakha stock—turned out to be almost identical. A significant similarity in the chemistry of major rock-forming minerals is established for spodumene granite porphyry of the Alakha stock and spodumene pegmatites from large deposits, which makes it possible to suggest that they are close in the petrogenetic mechanism of their formation. The mineral assemblages of muscovite albitite in the apical portion of the Alakha stock are connected by gradual transition with those of spodumene granite porphyry. Such a transition is caused by postmagmatic metasomatic alteration of the latter.

  1. Single-Beam Bathymetry Sounding Data of Cape Canaveral, Florida, (2014) gridded in ESRI GRID format

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Cape Canaveral Coastal System (CCCS) is a prominent feature along the Southeast U.S. coastline and is the only large cape south of Cape Fear, North Carolina....

  2. Lidar Bathymetry Data of Cape Canaveral, Florida, (2014) in XYZ ASCII text file format

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Cape Canaveral Coastal System (CCCS) is a prominent feature along the Southeast U.S. coastline and is the only large cape south of Cape Fear, North Carolina....

  3. Color coded bathmetry map of Cape Canaveral, Florida, derived from boat based sounding data (2014)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Cape Canaveral Coastal System (CCCS) is a prominent feature along the Southeast U.S. coastline and is the only large cape south of Cape Fear, North Carolina....

  4. Cape Cod Transit Task Force : Five-Year Public Transportation Plan

    Science.gov (United States)

    2002-06-30

    The U.S. Department of Transportation's Volpe National Transportation Systems : Center has been working in cooperation with the Cape Cod Regional Transit : Authority, the Cape Cod Commission, and other organizations participating on : the Cape Cod Tr...

  5. Igneous phenocrystic origin of K-feldspar megacrysts in granitic rocks from the Sierra Nevada batholith

    Science.gov (United States)

    Moore, J.G.; Sisson, T.W.

    2008-01-01

    Study of four K-feldspar megacrystic granitic plutons and related dikes in the Sierra Nevada composite batholith indicates that the megacrysts are phenocrysts that grew in contact with granitic melt. Growth to megacrystic sizes was due to repeated replenishment of the magma bodies by fresh granitic melt that maintained temperatures above the solidus for extended time periods and that provided components necessary for K-feldspar growth. These intrusions cooled 89-83 Ma, are the youngest in the range, and represent the culminating magmatic phase of the Sierra Nevada batholith. They are the granodiorite of Topaz Lake, the Cathedral Peak Granodiorite, the Mono Creek Granite, the Whitney Granodiorite, the Johnson Granite Porphyry, and the Golden Bear Dike. Megacrysts in these igneous bodies attain 4-10 cm in length. All have sawtooth oscillatory zoning marked by varying concentration of BaO ranging generally from 3.5 to 0.5 wt%. Some of the more pronounced zones begin with resorption and channeling of the underlying zone. Layers of mineral inclusions, principally plagioclase, but also biotite, quartz, hornblende, titanite, and accessory minerals, are parallel to the BaO-delineated zones, are sorted by size along the boundaries, and have their long axes preferentially aligned parallel to the boundaries. These features indicate that the K-feldspar megacrysts grew while surrounded by melt, allowing the inclusion minerals to periodically attach themselves to the faces of the growing crystals. The temperature of growth of titanite included within the K-feldspar megacrysts is estimated by use of a Zr-in-titanite geothermometer. Megacryst-hosted titanite grains all yield temperatures typical of felsic magmas, mainly 735-760 ??C. Titanite grains in the granodiorite hosts marginal to the megacrysts range to lower growth temperatures, in some instances into the subsolidus. The limited range and igneous values of growth temperatures for megacryst-hosted titanite grains support the

  6. Itokawa dust particles: a direct link between S-type asteroids and ordinary chondrites.

    Science.gov (United States)

    Nakamura, Tomoki; Noguchi, Takaaki; Tanaka, Masahiko; Zolensky, Michael E; Kimura, Makoto; Tsuchiyama, Akira; Nakato, Aiko; Ogami, Toshihiro; Ishida, Hatsumi; Uesugi, Masayuki; Yada, Toru; Shirai, Kei; Fujimura, Akio; Okazaki, Ryuji; Sandford, Scott A; Ishibashi, Yukihiro; Abe, Masanao; Okada, Tatsuaki; Ueno, Munetaka; Mukai, Toshifumi; Yoshikawa, Makoto; Kawaguchi, Junichiro

    2011-08-26

    The Hayabusa spacecraft successfully recovered dust particles from the surface of near-Earth asteroid 25143 Itokawa. Synchrotron-radiation x-ray diffraction and transmission and scanning electron microscope analyses indicate that the mineralogy and mineral chemistry of the Itokawa dust particles are identical to those of thermally metamorphosed LL chondrites, consistent with spectroscopic observations made from Earth and by the Hayabusa spacecraft. Our results directly demonstrate that ordinary chondrites, the most abundant meteorites found on Earth, come from S-type asteroids. Mineral chemistry indicates that the majority of regolith surface particles suffered long-term thermal annealing and subsequent impact shock, suggesting that Itokawa is an asteroid made of reassembled pieces of the interior portions of a once larger asteroid.

  7. Opportunity's Second Martian Birthday at Cape Verde

    Science.gov (United States)

    2007-01-01

    A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this approximate true-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days. The overall soft quality of the image, and the 'haze' seen in the lower right portion, are the result of scattered light from dust on the front sapphire window of the rover's camera. This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

  8. On the Structural Differences between Alumina-Supported CoMoS Type I and Alumina-, Silica-, and Carbon-Supported CoMoS Type II Phases Studied by XAFS, MES and XPS.

    NARCIS (Netherlands)

    Koningsberger, D.C.; Bouwens, S.M.A.M.; Zon, F.B.M. van; Dijk, M.P. van; Kraan, A.M. van der; Beer, V.H.J. de; Veen, J.A.R. van

    1994-01-01

    In this study the local structure of the Mo and Co promoter atoms in CoMoS type I and II on alumina, and CoMoS type II on various supports is compared using in situ XAFS spectroscopy as the main technique with XPS and MES in a supporting role. In the CoMoS phase the Co atoms are positioned at the

  9. Granite Rock Company; Proposed Settlement of Clean Water Act Class II Administrative Penalty Matter and Opportunity to Comment

    Science.gov (United States)

    Public Notice of Proposed Settlement of Clean Water Act Class II Administrative Penalty Matter and Opportunity to Comment In the Matter of Granite Rock Company, 350 Technology Drive, Watsonville, CA 95076

  10. Decay of granite monuments due to salt crystallization in a non-polluted urban environment

    Directory of Open Access Journals (Sweden)

    García-Talegón, J.

    1999-03-01

    Full Text Available The effect of salt crystallization on granite (s.l rocks used as building material in an urban environment with low atmospheric pollution was studied. The manners of salt crystallization and the subsequent deterioration caused were analyzed in unweathered granite and other fades which had undergone strong transformations in quarries before being used as stone materials, "alterites".

    Se estudia el efecto de la cristalización de sales solubles en rocas graníticas s.l empleadas como materiales de construcción, en ambiente urbano con baja contaminación atmosférica. Las formas en que cristalizan las sales y el deterioro asociado a su presencia son analizados en granitos sanos y en otras facies que han sufrido fuertes transformaciones en cantera previas a su empleo como materiales de construcción ("alteritas".

  11. The late Variscan ferroan granite magmatism of southern Sardinia: inferences from Mo metallogenesis

    Science.gov (United States)

    Naitza, Stefano; Conte, Aida Maria; Cuccuru, Stefano; Fadda, Sandro; Fiori, Maddalena; Oggiano, Giacomo; Secchi, Francesco

    2017-04-01

    Metallogeny is a powerful tool to investigate crustal evolution; a good example is offered by the Variscan basement of Sardinia and its Mo deposits. Mo ores are poorly represented in Variscan metallogenic provinces of Europe: however, in Sardinia, numerous small Mo deposits, often associated to Sn, W and F ores, are present, invariably related to an early Permian intrusive peak bracketed at about 290 Ma (Fadda et al., 2015; Naitza et al., 2017). In Sardinia, two main magmatic peaks have been schematized at pre-300 and 290 Ma. In southern Sardinia, the 290 magmatic peak is made up of several intrusive F-bearing rock-suites (Conte et al., 2016), belonging to ilmenite series, showing a slight peraluminous character and mostly classifiable as ferroan granites (sensu Frost and Frost, 2011). Mo-bearing granites form a distinct suite of relatively small plutons, emplaced at very shallow depth (about 1kb) in an exhumed Variscan low-grade basement. Peculiar characters of Mo-bearing granites are the occurrence of greisenized microgranite and granophyre cupolas, with fayalite-bearing pegmatites, and ilmenite, xenotime-(Y), monazite, fluorite, and local topaz as accessory phases. Recently, Conte et al. (2016) interpreted these granites as originated by partial melting of low crustal felsic metaigneous photoliths enriched in granophiles (Mo, Sn, W). Mo ores occur as: a) endo- and exo- quartz-muscovite greisens with molybdenite±Fe-Cu sulphides, and b) quartz-molybdenite±wolframite±Fe-Cu-Zn sulphides±fluorite±topaz hydrothermal veins and stockworks, hosted in granites or in country rocks. Redox state of magmas exerts a strong control on Mo metallogeny, as in Mo districts worldwide ores are usually hosted by high-fO2 magnetite series intrusions (Ishihara, 1981). The close field association of Sardinian Mo mineralization with ferroan, low-fO2 ilmenite-series granites may be explained in terms of Mo-enriched crustal sources of magmas, and very efficient geochemical

  12. Uranium mineralization in the two mica granite of gabal Ribdab area, South Eastern Desert, Egypt.

    Science.gov (United States)

    Ibrahim, M E; Saleh, G M; Abd El-Naby, H H

    2001-12-01

    Among the different rock units in the Gabal Ribdab area, the two-mica leucogranite and muscovite pegmatitic granite are the most favourable host rocks for uranium and thorium mineralization. The muscovite pegmatitic granite shows evidence of post-magmatic alteration, e.g. Na- and K-metasomatism, whereas the two-mica leucogranite could be regarded as being fresh. The spectrometric survey revealed the presence of three enriched zones with a maximum eU content of 140 ppm and the maximum eTh is 36 ppm. Uranophane, zippeite and becquerelite are the most abundant uranium minerals. The origin of these secondary minerals is mainly related to alteration of primary minerals by the action of oxidizing fluids, mobilization of uranium and then redeposition in other forms. Redistribution by circulating meteoric waters might have taken place.

  13. Layout Optimization for the Repository within a discontinuous and saturated granitic rock mass

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jhin Wung; Choi, Jong Won; Bae, Dae Seok

    2005-12-15

    The objective of the present study is a layout optimization of a single and double layer repositories within a repository site with special joint set arrangements. Single and double layer repository models, subjected to the variation of repository depth, cavern spacing, pitch, and layer spacing, are analyzed for the thermal, hydraulic, and mechanical interaction behavior during the period of 2000 years from waste emplacement. Material properties used for the granitic rock mass, rock joints, PWR spent fuel, disposal canister, compacted bentonite, backfill material, and groundwater are the data collected domestically, and foreign data are used for some of the data not available domestically. The repository model includes a saturated granitic rock mass with joints, PWR spent fuel in a disposal canister surrounded by compacted bentonite inside a deposition hole, and backfill material in the rest of the space within a repository cavern.

  14. Influence of the properties of granite and sandstone in the desalination process by electrokinetic technique

    DEFF Research Database (Denmark)

    Feijoo, J.; Ottosen, Lisbeth M.; Pozo-Antonio, J.S.

    2015-01-01

    such as sand disaggregation and superficial detachments. These problems can be solved by conservation technologies, which are aimed to decrease the salt concentration in rocks (desalination).The present study aimed to investigate the efficiency of electrokinetic techniques for desalination of two different......Soluble salts are considered a main cause of damage of porous building materials such as rocks, bricks or granites, which were commonly used in the building constructions of the architectural and archaeological heritage. Soluble salts are also responsible for various forms of deterioration...... kinds of rocks: granite and sandstone. These rocks were contaminated with NaCl solution, and samples with a thickness of 6. cm were used in the tests. This study compared the percentage of salt removal at different depths (efficacy) and the time needed to get the same percentage removal (effectiveness...

  15. The Pedregal granite (Portugal: petrographic and geochemical characterization of a peculiar granitoid

    Directory of Open Access Journals (Sweden)

    Ferreira, J. A.

    2014-12-01

    Full Text Available The Pedregal granite outcrops in the Central Iberian Zone, northern Portugal, in the eastern border of a synorogenic variscan granite-migmatite complex sub-concordant with the regional metamorphic structures. It is a granitoid (ca. 3 km2 with an elongated NW-SE shape intruded in staurolite-micaschist and banded gneiss-migmatite rocks, with local igneous breccias in the contact. The country rocks belong to a metapelitic and metasammitic sequence of Edicarian-Cambrian age, known as the “Complexo Xisto-Grauváquico” (CXG which shows a main regional foliation with a NW-SE to NNW-SSE direction. The Pedregal granite is peraluminous (its A/CNK parameter ranges from 1.18 to 1.62, with a magnesian and alkali to alkali-calcic signature. The peculiar features of the granite are high contents of Zr (389 to 435 ppm and a LREE flat pattern, which are uncommon characteristics for granitic rocks, as well as the corroded shape of the biotite, and the large amount of secondary muscovite. These peculiar features distinguish it from the adjacent synorogenic granites. The field, petrographical and chemical features of the Pedregal granite are in accordance with a second phase of partial melting of a residuum, depleted by melt segregation during a first melting episode with the involvement of peritectic garnet and abundant residual biotite with LREE- and Zr-bearing accessory minerals. Besides, the intrusive character of the granite, and the presence of metasedimentary xenoliths point out to a secondary diatexite.El granito de Pedregal aflora en la Zona Centro-Ibérica, en el norte de Portugal, en el borde oriental de un complejo granito-migmatítico sinorogénico varisco, subconcordante con las estructuras metamórficas regionales. Es un granitoide (ca. 3 km2 de forma elongada NW-SE, que intruye en micaesquistos estaurolíticos y en rocas gneissico- migmatíticas bandeadas, con brechas ígneas locales en el contacto. Las rocas encajantes pertenecen a una

  16. Simulation Of Aqua-Ammonia Refrigeration System Using The Cape-Open To Cape-Open COCO Simulator

    Directory of Open Access Journals (Sweden)

    Janavi Gohil

    2017-03-01

    Full Text Available In this paper we have simulated a flow sheet of aqua ammonia refrigeration system using Cape Open simulator. The main aim of writing this paper is to compare the results obtained from thermodynamic simulation of aqua ammonia refrigeration system and the results obtained from the flow sheet simulation in Cape-Open to Cape-Open COCO simulator. The corresponding COP values obtained from both the sources are calculated and compared. With the error being very minute the calculations using simulator prove to be more efficient and timesaving when compared to the results obtained by calculations done using tedious thermodynamic simulations and constant mass balance for different process conditions.

  17. U-Pb and Rb-Sr isotopic systematics of fluids associated with mineralization of the Dartmoor granite, southwest England

    Science.gov (United States)

    Wayne, David M.; Miller, Martin F.; Scrivener, Richard C.; Banks, David A.

    1996-02-01

    Quartz veins from early hydrothermal mineralization within the 280 Ma Dartmoor granite contain abundant fluid inclusions, which were sampled using crush-leach techniques and analyzed for Rb, Sr, U, and Pb content and isotopic ratios. The present-day lead isotopic signature of some of the crushleach fluids is similar to that of granitic alkali feldspars from Dartmoor and other localities in southwest England, although some fluid samples contain a more radiogenic Pb component. The more radiogenic fluids fell into, or near, the granitic K-feldspar field upon correction of the present-day fluid Pb ratios for in situ U decay over ca. 280 Ma, but the lead isotope ratios of the less-radiogenic fluids became significantly lower than that of the granitic K-feldspars. The apparent overcorrection may be real, or may reflect either fluid mixing due to leaching of secondary fluid inclusions, differential leaching of U and Pb, the presence of an undetermined U-rich included phase (or fracture-filling) within the quartz, or a combination of the above. The variation of fluid U/Pb ratios also suggests some complications regarding either the selective retention of U and Pb on quartz surfaces, or the presence of submicroscopic U-rich inclusions. Therefore, we suggest that in situ decay corrections to lead isotopic data obtained using crush-leach techniques be applied with great caution. The fluid 87Rb/ 86Sr values vary little (1.40-1.74), as do their present-day strontium isotope signatures ( 87Rb/ 86Sr = 0.71814-0.71968). When corrected for in situ 87Rb decay over 280 Ma, the fluids contain significant excess radiogenic Sr (Sr i = 0.7118-0.7141), relative to the Dartmoor granite S i (=0.7101). If the Sr in the fluids is derived exclusively from the granite, or some granite-related source, and closedsystem evolution of the Rb-Sr isotopic system is assumed, the amount of excess 87Sr is a function of the time difference between Sr closure in the granite and Sr closure in the vein. Age

  18. Radiometric evaluation of granite tables in environment public in the city of Recife-PE, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Edilson A.; Amaral, Romilton dos S.; Santos Junior, Jose A. dos; Bezerra, Jairo D., E-mail: accioly.edilson@ufpe.b, E-mail: romilton@ufpe.b, E-mail: jaraujo@ufpe.b, E-mail: jairo.dias@ufpe.b [Universidade Federal de Pernambuco (RAE/DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Radioecologia

    2011-07-01

    Granite in Pernambuco has been used as raw-material in several utensils, amongst which, furniture and decoration objects. This granite, besides being traded internally, is also exported to Asia and Europe. Differentiated content of some radionuclides of the ({sup 238}U and {sup 232}Th) and {sup 40}K natural series above average content of other rocks is also commonly found, due to its origin and geological formation. The gamma radiation stems from the decay of the given series, followed by the {sup 40}K, and it should not exceed the 1 mSv.y{sup -1} limit per person of the public, according to the current radiological protection rules (ICRP, 60). This work aimed to radiometrically assess the granite tables used by the public of a well visited restaurant in the city of Recife. It is expected to contribute to the environmental monitoring and to assess the possible health risks for humans. The tables were monitored for a period of about one year. Dosimetric tablets of CaSO{sub 4}:Dy were used. The findings showed doses ranges from the background to 4.7 mSv.y{sup -1}, with general average of dose rate equal to 3.0 mSv.y{sup -1}. Therefore, it was concluded that despite the average dose rates in the different granite objects studied being higher than the recommended rate, the exposure does not offer risks to their users, due to the contact time (meal time) and the levels of radioactive emission found. (author)

  19. Geochemistry of mylonitic tourmaline-bearing granite- gneiss pluton in the northeast of June mine

    Directory of Open Access Journals (Sweden)

    Arezoo Moradi

    2017-07-01

    Full Text Available Introduction Studied mylonitic granite-gneiss body is located in the Northwest of the Azna region in the Lorestan province close to the June dimension stone mine. It is a part of the metamorphic- magmatic complex including granite-gneiss, amphibolite, marble and schist. The crystalline basement is attributed to late-Neoproterozoic and it indicates a Panafrican basement, which yields a laser-ablation ICP–MS U–Pb zircon ages of 608 ± 18 Ma and 588 ± 41 Ma (Shakerardakani et al., 2015. There are two granite-gneiss plutons in the complex that are Galeh– Dezh (Shabanian et al., 2009, and June plutons. The Galeh-Doz pluton are previously proposed as syn-deformation pluton with a major S-shaped bend which has been imparted during dextral shearing with a Late Cretaceous (Mohajjel and Fergusson, 2000. However, new age dating on the pluton using U–Pb in the magmatic zircon produced the late-Neoproterozoic dates (Nutman et al., 2014; Shakerardakani et al., 2015. The granite-gneiss plutons show mylonitic fabrics and microstructures (Shabanian et al., 2010. The geochemical characteristics of mylonitic granite-gneiss body near June mine in NW Azna, is in the focus of our research. Materials and methods Petrographic investigations of 30 thin sections were made. Then eight samples were selected and analyzed for whole rock major, trace and REE compositions by ICP-emission spectrometry and ICP-mass spectrometry using natural rock standards as reference samples for calibration at the ACME Analytical Laboratories in Vancouver, British Columbia, Canada. Results The studied gneiss- granitic body has lepido-granoblastic texture as its major texture. It variably shows evidence of dynamic deformation from ultramylonite to protomylonite. The gneiss- granite consists of quartz, alkali feldspar (mostly as perthite, plagioclase, biotite, white mica (muscovite and phengitic muscovite. Accessory phases in the granitoid include, tourmaline, zircon, magmatic epidote

  20. Supernumerary registrar experience at the University of Cape Town ...

    African Journals Online (AJOL)

    Supernumerary Registrar Masters of Medicine Enrolment List 2012,. Postgraduate Medical Education Office, Faculty of Health Sciences,. University of Cape Town – unpublished). SNRs are not locally remunerated. Most SNRs originate from African countries ...

  1. Cape Cod National Seashore parking management system pilot synthesis

    Science.gov (United States)

    2013-12-27

    The Cape Cod National Seashore (CACO) has undertaken a program to improve parking management at its beach parking lots, and to provide information about parking availability to CACO visitors. This project will build upon work already accomplished, to...

  2. Cape Romain National Wildlife Refuge : Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Cape May NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  3. Tuberculosis in Cape Town: An age-structured transmission model

    Directory of Open Access Journals (Sweden)

    Nello Blaser

    2016-03-01

    Conclusion: The protective effect of a first latent infection on subsequent infections and the faster progression in previously treated patients are the key determinants of the age-structure of TB notification rates in Cape Town.

  4. Evidence of partial migratory behaviour by the Cape Griffon Gyps ...

    African Journals Online (AJOL)

    called East Cape Midlands, wherein 59% of respondents who reported the occurrence of griffons had a level of interest and awareness that enabled them to note seasonal occurrences; all stated that the griffons were observed 'only, or mainly, ...

  5. Pestalotioid fungi from Restionaceae in the Cape Floral Kingdom

    NARCIS (Netherlands)

    Lee, M.J.; Crous, P.W.; Wingfield, M.J.

    2006-01-01

    Eight pestalotioid fungi were isolated from the Restionaceae growing in the Cape Floral Kingdom of South Africa. Sarcostroma restionis, Truncatella megaspora, T. restionacearum and T. spadicea are newly described. New records include Pestalotiopsis matildae, Sarcostroma lomatiae, Truncatella betulae

  6. Pestalotioid fungi from Restionaceae in the Cape Floral Kingdom.

    NARCIS (Netherlands)

    Lee, S.; Crous, P.W.; Wingfield, M.J.

    2006-01-01

    Eight pestalotioid fungi were isolated from the Restionaceae growing in the Cape Floral Kingdom of South Africa. Sarcostroma restionis, Truncatella megaspora, T. restionacearum and T. spadicea are newly described. New records include Pestalotiopsis matildae, Sarcostroma lomatiae, Truncatella betulae

  7. Eastern Cape hybrid mini-grid systems - a case study

    CSIR Research Space (South Africa)

    Szewczuk, S

    2010-05-01

    Full Text Available This presentation provides a rationale for off-grid projects, and then briefly discusses renewable energy for rural electrification in the Eastern Cape. The impact of this project, and related research work, is also touched on....

  8. Cape Hatteras, North Carolina Tsunami Forecast Grids for MOST Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Cape Hatteras, North Carolina Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST)...

  9. Paradoxical helminthiasis and giardiasis in Cape Town, South Africa ...

    African Journals Online (AJOL)

    Paradoxical helminthiasis and giardiasis in Cape Town, South Africa: epidemiology and control. Vera J Adams, Miles B Markus, Joanita FA Adams, Esme Jordaan, Bronwyn Curtis, Muhammad A Dhansay, Charlie C Obihara, John E Fincham ...

  10. biodiversity status of urban remnant forests in cape coast, ghana

    African Journals Online (AJOL)

    User

    plant species that have disappeared from the Cape Coast environ and is worth ... gory, it is important to protect these native forests from total destruction. .... Methods for survey and handling of .... of depletion and extent of extinction of species.

  11. 2010 Cape Canaveral, Florida Single-beam Bathymetry Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetric surveys were conducted on July 27-29, 2010 along 37 cross-shore transects offshore from Cape Canaveral, Fla. The transects were spaced 500...

  12. Water Resources Inventory and Assessment: Cape May National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Water Resource Inventory and Assessment report for Cape May National Wildlife Refuge describes current hydrologic information, provides an assessment of water...

  13. GRIP BARBADOS/CAPE VERDE RADIOSONDE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Barbados/Cape Verde radiosonde data set consists of generally two soundings per day (06Z and 12Z) launched from Barbados, and one sounding per day (12Z)...

  14. Cape Peirce walrus and marine mammal censusing report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Population fluctuations and behavioral aspects of the Cape Peirce walrus herd was monitored and recorded by a field crew from June 1985 to October 1985, from May...

  15. Hydrodynamics, sediment transport and light extinction off Cape Bolinao, Philippines

    NARCIS (Netherlands)

    Rivera, P.C.

    1997-01-01

    Observational and numerical modelling studies of the hydrodynamics, sediment transport, and light extinction were undertaken in the marine environment around Cape Bolinao in the Lingayen Gulf (Northwest Philippines). Abundant with ecologically important seagrasses and benthic organisms,

  16. Mineralogy and mineral chemistry of rare-metal pegmatites at Abu Rusheid granitic gneisses, South Eastern desert, Egypt:

    OpenAIRE

    Mohamed Fahmy Raslan; ALI, MOHAMED A.

    2011-01-01

    The Abu Rushied area, situated in the South Eastern Desert of Egypt is a distinctive occurrence of economically important rare-metal mineralization where the host rocks are represented by granitic gneisses. Correspondingly, mineralogical and geochemical investigation of pegmatites pockets scattered within Abu Rusheid granitic gneisses revealed the presence of Hf-zircon, ferrocolumbite and uranyl silicate minerals (uranophane and kasolite). Electronmicroprobe analyses revealed the presence of ...

  17. Indoor radon risk associated to post-tectonic biotite granites from Vila Pouca de Aguiar pluton, northern Portugal.

    Science.gov (United States)

    Martins, L M O; Gomes, M E P; Teixeira, R J S; Pereira, A J S C; Neves, L J P F

    2016-11-01

    At Vila Pouca de Aguiar area, northern Portugal, crops out a post-tectonic Variscan granite pluton, related with the Régua-Vila Real-Verín fault zone, comprising three types of biotite granites. Among these granites, PSG granite yield the highest average contents of U, probably due to its enrichment in accessory U-bearing minerals such as zircon. In the proximity of faults and joints, these granites are often affected by different degrees of hydrothermal alteration, forming reddish altered rocks, commonly known as "episyenites". These altered rocks are probably associated to the occurrence of hydrothermal processes, which led to uranium enrichment in the most advanced stages of episyenitization. In these granites, both average gamma absorbed dose rates in outdoor and indoor air are higher than those of the world average. Furthermore, even in the worst usage scenario, all these granites can be used as a building material, since their annual effective doses are similar to the limit defined by the European Commission. The geometric mean of radon activity of 91 dwellings located at the Vila Pouca de Aguiar pluton is 568Bqm(-3), exceeding that of other northern Portuguese granites. Measurements carried out during a winter season, indicate that 62.6% of the analysed dwellings yield higher indoor radon average values than the Portuguese legislation limit (400Bqm(-3)), and annual effective doses due higher than the world's average value (1.2mSvy(-1)). The interaction of geogenic, architectural and anthropogenic features is crucial to explain the variance in the geometric mean of radon activity of dwellings from Vila Pouca de Aguiar pluton, but the role of geologic faults is probably the most important decisive factor to increase the indoor radon concentration in dwellings. Hence, the development of awareness campaigns in order to inform population about the incurred radiological risks to radon exposure are highly recommended for this specific area. Copyright © 2016

  18. Laser cleaning of graffiti in Rosa Porriño granite

    Science.gov (United States)

    Fiorucci, M. P.; Lamas, J.; López, A. J.; Rivas, T.; Ramil, A.

    2011-05-01

    This paper presents preliminary results in determining the optimum parameters for graffiti removal in a ornamental granite, Rosa Porriño, by means of Nd:YVO4 laser at the wavelength of 355 nm and different fluences. The spray-paints (black, blue, red and silver) tested in this work were chemically characterized by means of elemental analysis, XRF, SEM/EDX and FTIR. The assessment of cleaning and characterization of the stone substrate before and after irradiation was performed by means of optical microscopy, SEM-EDX, and confocal microscopy. The analysis of the irradiated samples showed in some cases, damage in the granite substrate associated to thermal effects. The severity and kind of damage, depends on the laser fluence delivered, the constituent mineral irradiated, and the color used to paint the stone. So, at the highest levels of fluence the laser beam is able to scratch the surface, being the depth of the grooves in the stone measured by confocal microscopy. Moreover, SEM images show the differential damage caused in mineral constituents of granite i.e., quartz, feldspars, and biotite, the latter providing to be the most affected mineral, reaching melting even at low levels of fluence. It was appreciated that the color of the spray-paint affects the results of cleaning, and observed differences could be attributed to different organic constituents in the paints or the presence of metallic particles in its composition, as occurs with silver paint.

  19. Initiation and propagation of mixed mode fractures in granite and sandstone

    Science.gov (United States)

    Rück, Marc; Rahner, Roman; Sone, Hiroki; Dresen, Georg

    2017-10-01

    We investigate mixed mode fracture initiation and propagation in experimentally deformed granite and sandstone. We performed a series of asymmetric loading tests to induce fractures in cylindrical specimens at confining pressures up to 20 MPa. Loading was controlled using acoustic emission (AE) feedback control, which allows studying quasi-static fracture propagation for several hours. Location of acoustic emissions reveals distinct differences in spatial-temporal fracture evolution between granite and sandstone samples. Before reaching peak stress in experiments performed on granite, axial fractures initiate first at the edge of the indenter and then propagate through the entire sample. Secondary inclined fractures develop during softening of the sample. In sandstone, inclined shear fractures nucleate at peak stress and propagate through the specimen. AE source type analysis shows complex fracturing in both materials with pore collapse contributing significantly to fracture growth in sandstone samples. We compare the experimental results with numerical models to analyze stress distribution and energy release rate per unit crack surface area in the samples at different stages during fracture growth. We thereby show that for both rock types the energy release rate increases approximately linearly during fracture propagation. The study illuminates how different material properties modify fracture initiation direction under similar loading conditions.

  20. Exploration of geo-mineral compounds in granite mining soils using XRD pattern data analysis

    Science.gov (United States)

    Koteswara Reddy, G.; Yarakkula, Kiran

    2017-11-01

    The purpose of the study was to investigate the major minerals present in granite mining waste and agricultural soils near and away from mining areas. The mineral exploration of representative sub-soil samples are identified by X-Ray Diffractometer (XRD) pattern data analysis. The morphological features and quantitative elementary analysis was performed by Scanning Electron Microscopy-Energy Dispersed Spectroscopy (SEM-EDS).The XRD pattern data revealed that the major minerals are identified as Quartz, Albite, Anorthite, K-Feldspars, Muscovite, Annite, Lepidolite, Illite, Enstatite and Ferrosilite in granite waste. However, in case of agricultural farm soils the major minerals are identified as Gypsum, Calcite, Magnetite, Hematite, Muscovite, K-Feldspars and Quartz. Moreover, the agricultural soils neighbouring mining areas, the minerals are found that, the enriched Mica group minerals (Lepidolite and Illite) the enriched Orthopyroxene group minerals (Ferrosilite and Enstatite). It is observed that the Mica and Orthopyroxene group minerals are present in agricultural farm soils neighbouring mining areas and absent in agricultural farm soils away from mining areas. The study demonstrated that the chemical migration takes place at agricultural farm lands in the vicinity of the granite mining areas.

  1. Hydric properties of some iberian ornamental granites with different superficial finishes: a petrophysical interpretation

    Directory of Open Access Journals (Sweden)

    Rojo, A.

    2003-03-01

    Full Text Available Some physical properties of three ornamental granites with different superficial finishes (polished, sawn and flamed were quantified by standard tests. These granites are commercially known as Rosa Porrino, Rosavel and Blanco Alcazar. The determined properties were: density, open porosity, water absorption, capillarity, evaporation, vapour absorption and water vapour permeability. The values of the hydric properties in the studied granites fundamentally depended on their textural characteristics, mainly grain size, micro cracking network and open porosity, and, to a lesser extent, on their superficial finish.

    El estudio analiza las diferencias en el comportamiento hídrico de tres granitos con diferentes acabados superficiales: pulido, corte de sierra y chorro de fuego. Estos granitos se comercializan con los nombres de Rosa Porrino, Rosavel y Blanco Alcázar. Las propiedades determinadas han sido: densidad, porosidad abierta, absorción libre de agua, absorción de vapor de agua, absorción de agua por capilaridad, evaporación y permeabilidad al vapor de agua. Los valores de las propiedades hídricas determinadas dependen fundamentalmente de las características texturales: tamaño de grano, microfisuras y porosidad abierta y, en menor medida, de los acabados superficiales.

  2. Experimental Investigation of Wave Velocity-Permeability Model for Granite Subjected to Different Temperature Processing

    Directory of Open Access Journals (Sweden)

    Guanghui Jiang

    2017-01-01

    Full Text Available Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.

  3. Deformation of partially molten granite: a review and comparison of experimental and natural case studies

    Science.gov (United States)

    Rosenberg, Claudio L.

    2001-05-01

    Experimental and natural investigations of partially molten granite are compared and reviewed. Experiments suggest that deformation of partially molten granite with low-viscosity melt (104 Pa s) exhibits a rheological critical melt percentage (RCMP). In case of high viscosity melts (108 Pa s), however, the relationship between melt fraction and log viscosity of the partially molten granite may be linear. Considerations about viscosity, rheological thresholds, and segregation of natural melts suggest that low-viscosity melt experiments simulate natural conditions more realistically. Therefore, an RCMP is to be expected under natural conditions. Both diffusion creep and dislocation creep may occur under natural conditions, whereas cataclastic flow is only observed under experimental conditions. A melt-induced transition from dislocation creep to diffusion creep occurs under experimental and natural conditions. Melt topology is controlled by the magnitude of differential stress under experimental conditions. If differential stress is higher than ~100-150 MPa, melt pockets are elongate and oriented at a low angle to the maximum compressive stress. In contrast, in nature, melt pockets tend to be oriented subparallel to the foliation plane, i.e., presumably at a high angle to the maximum compressive stress.

  4. Urban Ecology in Cape Town: South African Comparisons and Reflections

    OpenAIRE

    Sarel S. Cilliers; Stefan J. Siebert

    2012-01-01

    Little urban ecological research has been done in South Africa. The papers in the Ecology and Society special feature Urban Ecological and Social-Ecological Research in the City of Cape Town make, therefore, an important contribution to the development of urban ecology locally and globally. Different approaches have been used in the study of urban ecology of different urban areas in South Africa. Cape Town is situated in a biodiversity hotspot and is the only South African city which includes...

  5. Strategies GeoCape Intelligent Observation Studies @ GSFC

    Science.gov (United States)

    Cappelaere, Pat; Frye, Stu; Moe, Karen; Mandl, Dan; LeMoigne, Jacqueline; Flatley, Tom; Geist, Alessandro

    2015-01-01

    This presentation provides information a summary of the tradeoff studies conducted for GeoCape by the GSFC team in terms of how to optimize GeoCape observation efficiency. Tradeoffs include total ground scheduling with simple priorities, ground scheduling with cloud forecast, ground scheduling with sub-area forecast, onboard scheduling with onboard cloud detection and smart onboard scheduling and onboard image processing. The tradeoffs considered optimzing cost, downlink bandwidth and total number of images acquired.

  6. Radiation survey and decontamination of cape Arza from depleted uranium

    Directory of Open Access Journals (Sweden)

    Vukotić Perko

    2003-01-01

    Full Text Available In the action of NATO A-10 airplanes in 1999, the cape Arza, Serbia and Montenegro was contaminated by depleted uranium. The clean-up operations were undertaken at the site, and 242 uranium projectiles and their 49 larger fragments were removed from the cape. That is about 85% of the total number of projectiles by which Arza was contaminated. Here are described details of the applied procedures and results of the soil radioactivity measurements after decontamination.

  7. John Herschel and the Cape flora, 1834 - 1839.

    Science.gov (United States)

    Rourke, J. P.

    John Herschel's interest in botany was stimulated by his contact with the species-rich Cape flora while resident in Cape Town, 1834 - 1838. The comparative study of his extensive living collection of bulbous plants, mainly of the Iridaceae, Liliaceae, Amarayllidaceae and Orchidaceae led him to consider some basic aspects of the origin of species and of taxonomic theory, in letters to colleagues in Europe.

  8. Sources of granite magmatism in the Embu Terrane (Ribeira Belt, Brazil): Neoproterozoic crust recycling constrained by elemental and isotope (Sr-Nd-Pb) geochemistry

    Science.gov (United States)

    Alves, Adriana; Janasi, Valdecir de Assis; Campos Neto, Mario da Costa

    2016-07-01

    Whole rock elemental and Sr-Nd isotope geochemistry and in situ K-feldspar Pb isotope geochemistry were used to identify the sources involved in the genesis of Neoproterozoic granites from the Embu Terrane, Ribeira Belt, SE Brazil. Granite magmatism spanned over 200 Ma (810-580 Ma), and is dominated by crust-derived relatively low-T (850-750 °C, zircon saturation) biotite granites to biotite-muscovite granites. Two Cryogenian plutons show the least negative εNdt (-8 to -10) and highest mg# (30-40) of the whole set. Their compositions are strongly contrasted, implying distinct sources for the peraluminous (ASI ∼ 1.2) ∼660 Ma Serra do Quebra-Cangalha batholith (metasedimentary rocks from relatively young upper crust with high Rb/Sr and low Th/U) and the metaluminous (ASI = 0.96-1.00) ∼ 630 Ma Santa Catarina Granite. Although not typical, the geochemical signature of these granites may reflect a continental margin arc environment, and they could be products of a prolonged period of oceanic plate consumption started at ∼810 Ma. The predominant Ediacaran (595-580 Ma) plutons have a spread of compositions from biotite granites with SiO2 as low as ∼65% (e.g., Itapeti, Mauá, Sabaúna and Lagoinha granites) to fractionated muscovite granites (Mogi das Cruzes, Santa Branca and Guacuri granites; up to ∼75% SiO2). εNdT are characteristically negative (-12 to -18), with corresponding Nd TDM indicating sources with Paleoproterozoic mean crustal ages (2.0-2.5 Ga). The Guacuri and Santa Branca muscovite granites have the more negative εNdt, highest 87Sr/86Srt (0.714-0.717) and lowest 208Pb/206Pb and 207Pb/206Pb, consistent with an old metasedimentary source with low time-integrated Rb/Sr. However, a positive Nd-Sr isotope correlation is suggested by data from the other granites, and would be consistent with mixing between an older source predominant in the Mauá granite and a younger, high Rb/Sr source that is more abundant in the Lagoinha granite sample. The

  9. Elemental analysis of granite by instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF).

    Science.gov (United States)

    El-Taher, A

    2012-01-01

    The instrumental neutron activation analysis technique (INAA) was used for qualitative and quantitative analysis of granite samples collected from four locations in the Aswan area in South Egypt. The samples were prepared together with their standards and simultaneously irradiated in a neutron flux of 7×10(11)n/cm(2)s in the TRIGA Mainz research reactor. Gamma-ray spectra from an hyper-pure germanium detector were analyzed. The present study provides the basic data of elemental concentrations of granite rocks. The following elements have been determined Na, Mg, K, Fe, Mn, Sc, Cr, Ti, Co, Zn, Ga, Rb, Zr, Nb, Sn, Ba, Cs, La, Ce, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U. The X-ray fluorescence (XRF) was used for comparison and to detect elements, which can be detected only by XRF such as F, S, Cl, Co, Cu, Mo, Ni, Pb, Se and V. The data presented here are our contribution to understanding the elemental composition of the granite rocks. Because there are no existing databases for the elemental analysis of granite, our results are a start to establishing a database for the Egyptian granite. It is hoped that the data presented here will be useful to those dealing with geochemistry, granite chemistry and related fields. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Relations of zoned pegmatites to other pegmatites, granite, and metamorphic rocks in the southern Black Hills, South Dakota

    Science.gov (United States)

    Norton, J.J.; Redden, J.A.

    1990-01-01

    The pegmatite field and the Harney Peak Granite of the southern Black Hills, South Dakota, form an igneous system that progresses from slightly biotitic muscovite granite through layered pegmatitic granite, with alternating sodic and potassic rocks, to simple plagioclase-quartz-perthite pegmatites, and on to zoned pegmatites. Most of the country rocks are Lower Proterozoic mica schists. At 1700 Ga, intrusion of the Harney Peak Granite created a large dome in these rocks, a thermal aureole with a staurolite, a first sillimanite isograd, and a small area of metamorphism above the second sillimanite isograd. The zoned pegmatites have a strong tendency to occur in clusters, and the types of pegmatites are different in different clusters. A less obvious tendency is a regional zonation in which rare-mineral pegmatites become more abundant and muscovite pegmatites less abundant toward the outskirts of the region. The composition of the granite indicates that its magma originated by partial melting of metasedimentary mica schists similar to those at the present surface. The pegmatitic nature of most of the granite probably reflects exsolution of an aqueous phase. -from Authors

  11. Age, duration of formation, and geotectonic position of the Zavitaya lithium granite-pegmatite system, Eastern Transbaikalia

    Science.gov (United States)

    Zagorsky, V. Ye.; Shokalsky, S. P.; Sergeev, S. A.

    2015-01-01

    The Zavitaya granite-pegmatite system with a lithium deposit is localized in the northern marginal part of the Onon terrane (Aginskii massif) and ajoins to the Ingoda-Shilka branch of the Mongol-Okhotsk suture in the south. This paper presents the first U-Pb (SHRIMP) age of granites and barren and spodumene pegmatites of the Zavitaya field. The Zavitaya polychronous granite-pegmatite system evolved through 40 million years: porphyritic biotite granites (169.0 ± 3 Ma), two mica granites-leucogranites (147.5 ± 3.1 Ma), muscovite leucogranites (140.0 ± 3.0 Ma), barren pegmatites (139.6 ± 3.1 Ma), and lithium spodumem pegmatites (129.6 ± 2.7 Ma). The formation of the system coincides with the change in geodynamic regimes of the region at the Middle Jurassic-Early Cretaceous boundary: the age of the early granites of the system and spodumene pegmatites corresponds to the termination of collision and to the beginning of the Early Cretaceous rifting, respectively.

  12. Management of Oehler’s Type III Dens Invaginatus Using Cone Beam Computed Tomography

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    Jaya Ranganathan

    2016-01-01

    Full Text Available Dens Invaginatus is a dental malformation that poses diagnostic difficulties in the clinical context. This anomaly may increase the risk of pulp disease and can potentially complicate endodontic procedure due to the aberrant root canal anatomy. Compared to conventional radiographs, three-dimensional images obtained with Cone Beam Computed Tomography (CBCT are invaluable in the diagnosis of the extent of this anomaly and in the appropriate treatment planning. Oehler’s classification (1957 for Dens Invaginatus (DI into three types depending on the depth of the invagination has been used for treatment planning. Of the three types Type III DI is characterized by infolding of the enamel into the tooth up to the root apex and is considered as the most severe variant of DI and hence the most challenging to treat endodontically, due to the morphological complexities. This report describes a case of Oehler’s Type III DI in a necrotic permanent maxillary lateral incisor in which CBCT images played a key role in diagnosis and treatment planning. The case was managed successfully by a combination of nonsurgical and surgical endodontic therapy with orthograde and retrograde thermoplastic gutta percha obturation.

  13. Computational optimization for S-type biological systems: cockroach genetic algorithm.

    Science.gov (United States)

    Wu, Shinq-Jen; Wu, Cheng-Tao

    2013-10-01

    S-type biological systems (S-systems) are demonstrated to be universal approximations of continuous biological systems. S-systems are easy to be generalized to large systems. The systems are identified through data-driven identification techniques (cluster-based algorithms or computational methods). However, S-systems' identification is challenging because multiple attractors exist in such highly nonlinear systems. Moreover, in some biological systems the interactive effect cannot be neglected even the interaction order is small. Therefore, learning should be focused on increasing the gap between the true and redundant interaction. In addition, a wide searching space is necessary because no prior information is provided. The used technologies should have the ability to achieve convergence enhancement and diversity preservation. Cockroaches live in nearly all habitats and survive for more than 300 million years. In this paper, we mimic cockroaches' competitive swarm behavior and integrated it with advanced evolutionary operations. The proposed cockroach genetic algorithm (CGA) possesses strong snatching-food ability to rush forward to a target and high migration ability to escape from local minimum. CGA was tested with three small-scale systems, a twenty-state medium-scale system and a thirty-state large-scale system. A wide search space ([0,100] for rate constants and [-100,100] for kinetic orders) with random or bad initial starts are used to show the high exploration performance. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. 40 meter ESRI binary grid of swath bathymetry of inner continental shelf south of Cape Hatteras, NC to Cape Lookout, NC (shatt, UTM Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  15. Cape Verdean Notions of Migrant Remittances

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    Lisa Åkesson

    2011-10-01

    Full Text Available The transfer of money from migrants to their non-migrant relatives is a key, symbol of the quality and meaning of transnational kinship relations. This article analyses how people in Cape Verde view migrant family members’ economic obligations and it examines the concomitant moral discourse. Through a detailed ethnographic study the article explores how gender and kinship positions interplay with the moral obligation to send remittances, and it also inquires into the differences between rural and urban people’s attitudes towards monetary gifts. Moreover, the importance of the receiver’s status in the local society is discussed and the role of the personal relation between the sender and the receiver. Thus the analysis goes beyond an instrumental and rationalistic approach to remittances, which is common in much research, and explores the significance of this money for emotions and social relations.Para os seus parentes não emigrantes as remessas dos emigrantes são um símbolo chave da qualidade e do significado das relações de parentesco transnacionais. Este artigo analisa como as pessoas em Cabo Verde encaram as obrigações económicas dos emigrantes membros de família e examina o discurso moral concomitante. Através de um estudo etnográfico detalhado o artigo explora como posições de género e parentesco interagem com a obrigação moral de enviar remessas e também investiga as diferenças entre as atitudes das pessoas rurais e urbanas relativamente às ofertas monetárias. Além disso, discute-se a importância do estatuto do receptor na sociedade local e o papel da relação pessoal entre remetente e receptor. Assim, a análise vai além de uma abordagem instrumental e racionalista das remessas, o que é habitual em muitas pesquisas, explorando o significado deste dinheiro em termos de emoções e relações sociais.

  16. Petrogenesis of the Paleoproterozoic rapakivi A-type granites of the Archean Carajás metallogenic province, Brazil

    Science.gov (United States)

    Dall'Agnol, Roberto; Teixeira, Nilson P.; Rämö, O. Tapani; Moura, Candido A. V.; Macambira, Moacir J. B.; de Oliveira, Davis C.

    2005-03-01

    Three Paleoproterozoic A-type rapakivi granite suites (Jamon, Serra dos Carajás, and Velho Guilherme) are found in the Carajás metallogenic province, eastern Amazonian craton. Liquidus temperatures in the 900-870 °C range characterize the Jamon suite, those for Serra dos Carajás and Velho Guilherme are somewhat lower. Pressures of emplacement decrease from Jamon (3.2±0.7 kbar) through Serra dos Carajás (2.0±1.0 kbar) to Velho Guilherme (1.0±0.5 kbar). Oxidizing conditions (NNO+0.5) characterized the crystallization of the Jamon magma, the Velho Guilherme magmas were reducing (marginally below FMQ), and the Serra dos Carajás magmas were intermediate between the two in this respect. The three granite suites have Archean T DM model ages and strongly negative ɛNd values (-12 to -8 at 1880 Ma), and they were derived from Archean crust. The Jamon granite suite may have been derived from a quartz dioritic source, and the Velho Guilherme granites from K-feldspar-bearing granitoid rocks with some sedimentary input. The Serra dos Carajás granites either had a somewhat more mafic source than Velho Guilherme or were derived by a larger degree of melting. Underplating of mafic magma was probably the heat source for the melting. The petrological and geochemical characteristics of the Carajás granite suites imply considerable compositional variation in the Archean of the eastern Amazonian craton. The oxidized Jamon suite granites are similar to the Mesoproterozoic magnetite-series granites of Laurentia, and they were derived from Archean igneous sources that were more oxidized than the sources of the Fennoscandian rapakivi granites. The Serra dos Carajás and Velho Guilherme granites approach the classic reduced rapakivi series of Fennoscandia and Laurentia. No counterparts of the Mesoproterozoic two-mica granites of Laurentia have been found, however. Following the model of Hoffman [Hoffman, P., 1989. Speculations on Laurentia's first gigayear (2.0 to 1.0 Ga

  17. The story of heart transplantation: From cape town to cape comorin

    Directory of Open Access Journals (Sweden)

    Aakshi Kalra

    2016-01-01

    Full Text Available Norman Shumway is widely regarded as the father of heart transplantation although the world's first adult human heart transplant was performed by Christiaan Barnard, on December 3, 1967, at the Groote Schuur Hospital in Cape Town, South Africa. Adrian Kantrowitz performed the world's first pediatric heart transplant on December 6, 1967 and Norman Shumway performed the first adult heart transplant in the United States on January 6, 1968, at the Stanford University Hospital. In India, PK Sen attempted the first heart transplant in humans soon after Christaan Barnaard but the first and subsequent patients died. The first successful heart transplant in India was by Dr. P Venugopal in 1994 at AIIMS, New Delhi. This was followed soon after by Dr. KM Cherian who also did the first pediatric and first heart lung transplant in India.

  18. Differential Roles of Environmental Enrichment in Alzheimer’s Type of Neurodegeneration and Physiological Aging

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    Vladimir V. Salmin

    2017-07-01

    Full Text Available Impairment of hippocampal adult neurogenesis in aging or degenerating brain is a well-known phenomenon caused by the shortage of brain stem cell pool, alterations in the local microenvironment within the neurogenic niches, or deregulation of stem cell development. Environmental enrichment (EE has been proposed as a potent tool to restore brain functions, to prevent aging-associated neurodegeneration, and to cure neuronal deficits seen in neurodevelopmental and neurodegenerative disorders. Here, we report our data on the effects of environmental enrichment on hippocampal neurogenesis in vivo and neurosphere-forming capacity of hippocampal stem/progenitor cells in vitro. Two models – Alzheimer’s type of neurodegeneration and physiological brain aging – were chosen for the comparative analysis of EE effects. We found that environmental enrichment greatly affects the expression of markers specific for stem cells, progenitor cells and differentiated neurons (Pax6, Ngn2, NeuroD1, NeuN in the hippocampus of young adult rats or rats with Alzheimer’s disease (AD model but less efficiently in aged animals. Application of time-lag mathematical model for the analysis of impedance traces obtained in real-time monitoring of cell proliferation in vitro revealed that EE could restore neurosphere-forming capacity of hippocampal stem/progenitor cells more efficiently in young adult animals (fourfold greater in the control group comparing to the AD model group but not in the aged rats (no positive effect of environmental enrichment at all. In accordance with the results obtained in vivo, EE was almost ineffective in the recovery of hippocampal neurogenic reserve in vitro in aged, but not in amyloid-treated or young adult, rats. Therefore, EE-based neuroprotective strategies effective in Aβ-affected brain could not be directly extrapolated to aged brain.

  19. The Influence of Temperature on Time-Dependent Deformation and Failure in Granite: A Mesoscale Modeling Approach

    Science.gov (United States)

    Xu, T.; Zhou, G. L.; Heap, Michael J.; Zhu, W. C.; Chen, C. F.; Baud, Patrick

    2017-09-01

    An understanding of the influence of temperature on brittle creep in granite is important for the management and optimization of granitic nuclear waste repositories and geothermal resources. We propose here a two-dimensional, thermo-mechanical numerical model that describes the time-dependent brittle deformation (brittle creep) of low-porosity granite under different constant temperatures and confining pressures. The mesoscale model accounts for material heterogeneity through a stochastic local failure stress field, and local material degradation using an exponential material softening law. Importantly, the model introduces the concept of a mesoscopic renormalization to capture the co-operative interaction between microcracks in the transition from distributed to localized damage. The mesoscale physico-mechanical parameters for the model were first determined using a trial-and-error method (until the modeled output accurately captured mechanical data from constant strain rate experiments on low-porosity granite at three different confining pressures). The thermo-physical parameters required for the model, such as specific heat capacity, coefficient of linear thermal expansion, and thermal conductivity, were then determined from brittle creep experiments performed on the same low-porosity granite at temperatures of 23, 50, and 90 °C. The good agreement between the modeled output and the experimental data, using a unique set of thermo-physico-mechanical parameters, lends confidence to our numerical approach. Using these parameters, we then explore the influence of temperature, differential stress, confining pressure, and sample homogeneity on brittle creep in low-porosity granite. Our simulations show that increases in temperature and differential stress increase the creep strain rate and therefore reduce time-to-failure, while increases in confining pressure and sample homogeneity decrease creep strain rate and increase time-to-failure. We anticipate that the

  20. Environmental Radioactivity : a case study in HHP granitic region of Tusham ring complex Haryana, India

    Science.gov (United States)

    Bajwa B., S.; Singh, H.; Singh, J.; Singh, S.; Sonikawade R., G.

    2010-05-01

    The paper presents the results of investigations of radon levels in the soil-gas, groundwater and indoor-air in the dwellings of the high heat producing (HHP)-granitic region of Tusham ring complex, Bhiwani District, Haryana. Radon release from soil and groundwater was found to be comparatively higher than the values observed in the nearby non-HHP/non-granitic regions of Punjab. The soil-gas and the groundwater radon concentration of HHP region of Tusham ring conmplex varies from 42.8±0.7 - 71.5±3.2 kBq m-3 with an average value of 61 kBq m-3, and 17.4±1.3 - 49.7±1.7 Bq l-1 with an average of 26.2 Bq l-1respectively, whereas in non-granitic/non-HHP regions the average value 31.5 (16.3±0.8-44.1±1.8) kBq m-3 and 7.9 (4.7±0.7-14.0±1.2) Bql-1 respectively have been observed. Indoor radon concentration in around 155 traditional dwellings in a wide range of villages situated in this HHP region has also been measured using the SSNTDs (LR-115) for two continuous years. Indoor radon levels in these dwellings in these dwellings have been found to be varying from 109 ± 80 to 1006 ± 55 Bq m-3 whereas the annual average radon values vary from 60 ±37 to 235 ±55 Bq m-3 for the dwellings of the villages studied in a non-HHP region of Amritsar District, Punjab. A positive correlation has been observed between the soil-gas and indoor radon levels particularly in the periphery of the exposed HHP rock formations, which may likely be the result of the imfluence of imbeded and exposed HHP granitic rocks and thus the active-soil formations. In the present study, uranium concentration and radon exhalation rate in the wide range of soil/rock samples collected from this region, known to be composed of acid volcanics & associated HHP granites have been estimated. For comparative analysis, the soil samples from some districts of Punjab have also been analyzed for uranium estimation and radon exhalation rate. The ‘ CAN ' technique using plastic track detector LR-115 type-II has

  1. Crustal development in relation to granitic magmatism in regard to D/H partition between coexisting hornblende and biotite in the Svecofennian belt

    Directory of Open Access Journals (Sweden)

    Kuroda, Y.

    1993-12-01

    Full Text Available Tie-lines in the σD-XFe diagram of hornblende and biotite in Japanese island arc granites give commonly a similar slope to that derived from the equation of Suzuoki-Epstein's experimental work ( 1976. This indicates that in the process of granite intrusion in the island arc environment, the water/rock ratio is high enough to allow the presence of molecular water within and around the rock mass crystallizing from the magma. However, the tie-lines of the anorogenic rapakivi granites of Finland (age 1.65-1.54 Ga are quite different from those of island arc granites, i.e. the σD of hornblende is much lower than that of biotite and the XFe values of both of the minerals are almost the same and high (0.8-0.9. Thus, the tie-lines are nearly vertical. Moreover, the OH contents of hornblende and biotite are very low and this suggests the absence of molecular water in the ascending and crystallizing granitic magma. This probably suggests that the D/H fractionation factor between the hydrous silicates and hydroxyl (OH in the magma without molecular water is different from that of the island arc granites with plenty of molecular water. For the Svecofennian granitic rocks which are older than the rapakivi, e.g. the Turku, Uppsala, Vänge and Revsund masses, the σD-XFe relationships of hornblende and biotite change systematically following the chronological order of the intrusion. The σD-XFe relationships of the granitic rocks around Turku are close to those of the island arc granites, those of the Uppsala and Vänge granites show the intermediate patterns between the Turku and Revsund, and those of the Revsund granites are rather similar to rapakivi. It is considered that the geological settings of granitic magmatism in the Svecofennian belt of the Baltic shield developed from a more mobile to a more continental one.

  2. The nature and barium partitioning between immiscible melts - A comparison of experimental and natural systems with reference to lunar granite petrogenesis

    Science.gov (United States)

    Neal, C. R.; Taylor, L. A.

    1989-01-01

    Elemental partitioning between immiscible melts has been studied using experimental liquid-liquid Kds and those determined by analysis of immiscible glasses in basalt mesostases in order to investigate lunar granite petrogenesis. Experimental data show that Ba is partitioned into the basic immiscible melt, while probe analysis results show that Ba is partitioned into the granitic immiscible melt. It is concluded that lunar granite of significant size can only occur in a plutonic or deep hypabyssal environment.

  3. Common neuromusculoskeletal injuries amongst rock climbers in the Western Cape

    Directory of Open Access Journals (Sweden)

    Liezel Wegner

    2015-04-01

    Full Text Available Background: Rock climbing is an extreme sport that is fast gaining interest in the Western Cape. Due to the physical nature of the sport, climbers often suffer neuromusculoskeletal (NMS injuries. Physiotherapists are first-line practitioners who diagnose and treat NMS injuries, but no previous study has been conducted regarding common NMS injuries amongst rock climbers in the Western Cape.Objective: To determine the common NMS injuries amongst rock climbers, and the relationships between independent variables and injury.Method: A Quantitative, cross-sectional, retrospective descriptive study design utilised a self-developed survey based on the literature. This was completed by rock climbers from an indoor climbing gym in Cape Town and two outdoor crags in the Western Cape. Out of the total population of 650 climbers, 247 were conveniently sampled to complete the self-administered survey, making the results generalisable to the climbing population.Results: Finger flexor tendon pulley injuries were the most commonly diagnosed NMS injury. Injury to the fingers, hand and elbow regions were the most common self-reported injury by area. The risk of suffering climbing-related injuries was significantly correlated to gender, setting, grade and type of climbing, but not to frequency of climbing.Conclusion: The results of this study could assist physiotherapists to assess and manage the common NMS injuries that occur in this group of extreme athletes, as well as to raise awareness amongst rock climbers in the Western Cape about potential risk of injury.

  4. Foraging range and habitat use by Cape Vulture Gyps coprotheres from the Msikaba colony, Eastern Cape province, South Africa

    Directory of Open Access Journals (Sweden)

    Morgan B. Pfeiffer

    2015-03-01

    Full Text Available Despite the extent of subsistence farmland in Africa, little is known about endangered species that persist within them. The Cape Vulture (Gyps coprotheres is regionally endangered in southern Africa and at least 20% of the population breeds in the subsistence farmland area previously known as the Transkei in the Eastern Cape province of South Africa. To understand their movement ecology, adult Cape Vultures (n = 9 were captured and fitted with global positioning system/global system for mobile transmitters. Minimum convex polygons (MCPs,and 99% and 50% kernel density estimates (KDEs were calculated for the breeding and non breeding seasons of the Cape Vulture. Land use maps were constructed for each 99% KDE and vulture locations were overlaid. During the non-breeding season, ranges were slightly larger(mean [± SE] MCP = 16 887 km2 ± 366 km2 than the breeding season (MCP = 14 707 km2 ± 2155 km2. Breeding and non-breeding season MCPs overlapped by a total of 92%. Kernel density estimates showed seasonal variability. During the breeding season, Cape Vultures used subsistence farmland, natural woodland and protected areas more than expected. In the non-breeding season, vultures used natural woodland and subsistence farmland more than expected, and protected areas less than expected. In both seasons, human-altered landscapes were used less, except for subsistence farmland.Conservation implications: These results highlight the importance of subsistence farm land to the survival of the Cape Vulture. Efforts should be made to minimise potential threats to vultures in the core areas outlined, through outreach programmes and mitigation measures.The conservation buffer of 40 km around Cape Vulture breeding colonies should be increased to 50 km.

  5. Granitoid magmatism of Alarmaut granite-metamorphic dome, West Chukotka, NE Russia

    Science.gov (United States)

    Luchitskaya, M. V.; Sokolov, S. D.; Bondarenko, G. E.; Katkov, S. M.

    2009-04-01

    Main tectonic elements of West Chukotka are Alazey-Oloy, South-Anyui and Anyui-Chukotka fold systems, formed as a result of collision between structures of North-Asian continent active margin and Chukotka microcontinent [1-3]. South-Anyui fold system, separating Alazey-Oloy and Anyui-Chukotka systems, is considered as suture zon, formed as a result of oceanic basin closing [4-6]. Continent-microcontinent collision resulted in formation of large orogen with of northern and southern vergent structures, complicated by strike-slip deformations [7, 8]. Within Anyui-Chukotka fold system several rises, where most ancient deposits (crystalline basement and Paleozoic cover of Chukotka microcontinent) are exposed, were distinguished [2, 9-11]. Later they were considered as granite-metamorphic domes [12-14]. Alarmaut dome is located at West Chukotka to the north from Bilibino city and is traced from south to north in more than 120 km. General direction of structure is discordant to prevailing NW extensions of tectonic elements of the region. Paleozoic-Triassic deposits are exposed within the Alarmaut dome: 1) D3-C1 - crystalline schists, quartz-feldspar metasandstones, quartzites, marbles (700 m) [11]; 2) C1 - marblized limestones, quartz-feldspar metasandstones, quartzites, amphibole-pyroxene crystalline schists. Limestones contain corals, indicating Visean age of deposits [11]. Metamorphism reaches amphibolite facies, maximum P-T conditions are 660°С and 5 kbar. Migmatites, indicating in situ partial melting, are observed. Intensity of deformations of Paleozoic rocks increases at the boundary with Triassic deposits [11]; in the western part of dome slices of Pz rocks are separated by blastomylonite horizons [14]. Within Alramaut dome granitoids of Lupveem batholith (central part of dome), Bystrinsky pluton (southeastern part), and small Koyvel' and Kelil'vun plutons were studied. New U-Pb SHRIMP zircon data indicate Early Cretaceous (117-112 m.a.) age of granitoids [15

  6. An experimental study on the brittle-plastic transition during deformation of granite

    Science.gov (United States)

    Dang, Jiaxiang; Zhou, Yongsheng; Rybacki, Erik; He, Changrong; Dresen, Georg

    2017-05-01

    Naturally and experimentally deformed samples of granite show that the deformation mechanisms of plagioclase and K-feldspar are different. To investigate these mechanisms and the brittle-plastic transition that takes place in granitic rocks composed of quartz, plagioclase, and K-feldspar, five leucosome granite samples were deformed with a constant strain rate of 10-5 s-1 at different temperatures from 850 °C to 1050 °C and confining pressure (CP) of 300 MPa using a Paterson-type gas deformation apparatus. To consider pressure effects, two more samples were deformed at 950 °C but with different CPs, one with CP = 100 kPa and the other with CP = 100 MPa. In addition, an eighth sample was deformed under torsion shear at 950 °C with CP = 400 MPa. Microstructures of an undeformed sample and experimentally deformed samples were analyzed using an optical microscope and a scanning electron microscope. The granite is composed of about 36 volume percent quartz, ∼26% plagioclase, ∼34% microcline, ∼3% muscovite, and ∼1% chlorite. The stress-strain curves for all but two samples display weakening. The two exceptions are the sample that deformed with steady-state creep under a CP of 100 MPa and the sample that displayed brittle fracture under a CP of 100 kPa. For the other samples, peak strengths decreased with increasing temperature or lower CP. Microstructures show that samples underwent a brittle-plastic transition with increasing temperature. Samples fractured by cataclastic flow at 850 °C with CP = 300 MPa and at 950 °C with CP = 100 kPa. Microcline deformed by cataclastic flow at 900-1050 °C with CP = 100-400 MPa accompanied by dislocation glide at temperatures of 1000 °C and 1050 °C. At 900-1050 °C with CP = 100-400 MPa, plagioclase displayed bulging recrystallization and grain boundary migration recrystallization and quartz deformed by subgrain rotation recrystallization. Diffusion rims were observed between quartz, plagioclase, and microcline grain

  7. Hydrothermal REE and Zr Ore Forming Processes in Peralkaline Granitic Systems

    Science.gov (United States)

    Gysi, A. P.

    2015-12-01

    Anorogenic peralkaline igneous systems display extreme enrichment of REE and Zr with a hydrothermal overprint leading to post-magmatic metal mobilization. Strange Lake in Canada, for example, is a mid-Proterozoic peralkaline granitic intrusion and host to a world-class REE-Zr deposit with >50 Mt ore (>1.5 wt.% REE and >3 wt.% Zr). In contrast to porphyry systems, peralkaline systems are poorly understood and hydrothermal metal mobilization models are only in the early stage of their development. This is partly due to the paucity of thermodynamic data for REE-bearing minerals and aqueous species, and the complexity of the hydrothermal fluids (enrichment of F, P and Cl), which make it difficult to develop thermodynamic models of metal partitioning. This study aims to show the link between alteration stages and metal mobilization using Strange Lake as a natural laboratory and combine these observations with numerical modeling. Four types of alteration were recognized at Strange Lake: i) alkali (i.e. K and Na) metasomatism related to interaction with NaCl-bearing orthomagmatic fluids, ii) acidic alteration by HCl-HF-bearing fluids originating from the pegmatites followed by iii) aegirinization of the border of the pegmatites and surrounding granites and by iv) pervasive Ca-F-metasomatism. The acidic alteration accounts for most of the hydrothermal metal mobilization in and outward from the pegmatites, whereas the Ca-F-metasomatism led to metal deposition and resulted from interaction of an acidic F-rich fluid with a Ca-bearing fluid. Numerical simulations of fluid-rock reactions with saline HCl-HF-bearing fluids at 400 °C to 250 °C indicate that temperature, availability of F/Cl and pH limit the mobility of Zr and REE. Fluids with pH peralkaline granitic systems is the formation of a fluid-buffered subsystem providing the acids and ligands required for REE and Zr mobilization.

  8. Granites of the Southern Mongolia Carboniferous Arc: New geochronological and geochemical constraints

    Science.gov (United States)

    Blight, James H. S.; Crowley, Quentin G.; Petterson, Michael G.; Cunningham, Dickson

    2010-04-01

    The crust in southern Mongolia is part of the Central Asian Orogenic Belt, a vast accretionary orogen that records the opening and closure of the Palaeo-asian Ocean in the late Proterozoic to Palaeozoic. The crustal evolution of the region is revealed in basement inliers that also contain intrusion-related porphyry ore bodies that are important mineral exploration targets. The Saykhandulaan inlier in Southeast Mongolia is a Devonian-Carboniferous segment of island-arc crust, which is dominantly composed of extrusive and sedimentary lithologies, but which also contains the Oyut Ulaan I-type quartz-monzonite intrusion. A U-Pb zircon age for the Oyut Ulaan monzonite indicates emplacement at 330.0 ± 0.5 Ma. To the east of the Saykhandulaan inlier, intrusive complexes dominate the neighbouring Mandakh inlier. New ages are presented for four of these plutons; the Bronze Fox granodiorite (333.6 ± 0.6 Ma); the Narin Hudag monzonite (333.2 ± 0.6 Ma); the Shuteen quartz monzonite (325.5 ± 1.0 Ma); and the North Mandakh granite (292.3 ± 0.5). The intrusive bodies of the Saykhandulaan and Mandakh inliers have two distinct geochronological and geochemical associations: 1) mid-Carboniferous I-type monzonites that constitute the most easterly intrusive expression of the Southern Mongolia Carboniferous Arc and, 2) Early Permian A-type and peralkaline granites that represent a post-orogenic phase of voluminous granite emplacement. Both groups are significantly younger than the nearby Oyu Tolgoi and Tsagaan Suvarga Cu-porphyry ore bodies, which have previously been dated as early- and late-Devonian respectively. The new data presented here provide constraints on the timing of the transition from island-arc magmatism to post-collisional extension-related magmatism in the region and possible controls on fertile and infertile granitoid intrusions with respect to Cu-Au mineralisation.

  9. Exploring rock fissures: does a specialized root morphology explain endemism on granite outcrops?

    Science.gov (United States)

    Poot, Pieter; Hopper, Stephen D; van Diggelen, Josepha M H

    2012-07-01

    Worldwide, many plant species are confined to open, shallow-soil, rocky habitats. Although several hypotheses have been proposed to explain this habitat specificity, none has been convincing. We suggest that the high level of endemism on shallow soils is related to the edaphic specialization needed to survive in these often extremely drought-prone habitats. Previous research has shown that species endemic to ironstone communities in SW Australia have a specialized root morphology that enhances their chance to access fissures in the underlying rock. Here we test the generality of these findings for species that are confined to a shallow-soil habitat that is of much greater global significance: granite outcrops. We compared temporal and spatial root growth and allocation of three endemic woody perennials of SW Australian granite outcrop communities with those of congeners occurring on nearby deeper soils. Seedlings of all species were grown in 1·2 m long custom-made containers with a transparent bottom that allowed monitoring of root growth over time. The granite outcrop endemics mostly differed in a predictable way from their congeners from deeper soils. They generally invested a larger portion of their biomass in roots, distributed their roots faster and more evenly over the container and had a lower specific root length. In different species pairs the outcrop endemics achieved their apparent advantage by a different combination of the aforementioned traits. Our results are consistent with earlier work, indicating that species restricted to different types of drought-prone shallow-soil communities have undergone similar selection pressures. Although adaptive in their own habitat in terms of obtaining access to fissures in the underlying rock, these root system traits are likely to be maladaptive in deeper soil habitats. Therefore, our results may provide an explanation for the narrow endemism of many shallow-soil endemics.

  10. Geology, structure, geochemistry and ASTER-based mapping of Neoproterozoic Gebel El-Delihimmi granites, Central Eastern Desert of Egypt

    Science.gov (United States)

    Asran, Asran Mohamed; Emam, Ashraf; El-Fakharani, Abdelhamid

    2017-06-01

    The Gebel El-Delihimmi granite intrusion, located in the Central Eastern Desert of Egypt, cuts the core of a major anticlinal structure of calc-alkaline metavolcanics and ophiolitic mélange rocks. The intrusion is microscopically differentiated into granodiorite, monzogranite, syenogranite and alkali-feldspar granite. Decorrelation stretch and band-ratio techniques were applied to Advanced Spaceborne Thermal Emission and Reflection Radiometer data. Processing of ASTER-SWIR bands enabled discrimination of El-Delihimmi granite phases and generation of a detailed lithologic map of the study area. The structural and microfabric data suggest that the El-Delihimmi granite underwent at least two phases of deformations. The first was related to the Najd fault system during which the older granodiorite phase of the intrusion was affected by sinistral ductile shearing. During the second phase, monzogranite and syenogranite in the intrusion were affected by brittle E-W compressional deformation. Geochemical data reported here reveal that the granodiorite phase has K2O/Na2O ratio 1. The granite phases are generally I-type, metaluminous to slightly peraluminous and are interpreted as formed above subducted slabs of oceanic lithosphere rather than in continental collision zones.

  11. The Maua granitic massif, Central Ribeira Belt, Sao Paulo, Brazil: petrography, geochemistry and U-Pb dating

    Energy Technology Data Exchange (ETDEWEB)

    Filipov, Marcelo [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia de Minas]. E-mail: filipov@usp.br; Janasi, Valdecir de Assis [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias]. E-mail: vajanasi@usp.br

    2001-09-01

    The Maua granitic massif is an elongated body dominated by a porphyritic biotite monzogranite which grades, in its southwestern extremity, to lighter equi granular granite and greisenized (tourmaline)-biotite-muscovite leuco granite. Abundant enclaves can be divided in three types: grey micro granular enclaves, with rounded shapes and igneous textures, are compositionally similar to the enclosing porphyritic granites; dark, rounded, micaceous enclaves have high K/Na, and may correspond to highly assimilated meta sedimentary xenoliths; and angulous gneiss xenoliths seem to be fragments of an unexposed type of country rock. The primitive magmas that formed the massif were Zr, P and LREE-saturated, and became progressively enriched in U, Cs, Y, HREE, F and possibly Ta. Geochemical data show that most of the observed compositional variation can be a reflection of crystal fractionation at the level of emplacement. However, other processes such as magma mixing, contamination and post-magmatic alteration seem to respond for local chemical variations. U-Pb monazite dating point to a crystallization age of 588 {+-} 2 Ma which is ca. 20 myr. younger than those of nearby crust-derived syn-orogenic granites. (author)

  12. Uranium in granites from the Southwestern United States: actinide parent-daughter systems, sites and mobilization. First year report

    Energy Technology Data Exchange (ETDEWEB)

    Silver, L T; Williams, I S; Woodhead, J A

    1980-10-01

    Some of the principal findings of the study on the Lawler Peak Granite are: the granite is dated precisely by this work at 1411 +- 3 m.y., confirming its synchroneity with a great regional terrane of granites. Uranium is presently 8-10 times crustal abundance and thorium 2-3 times in this granite. Uranium is found to be enriched in at least eight, possibly ten, primary igneous mineral species over the whole-rock values. Individual mineral species show distinct levels in, and characteristics ranges of, uranium concentration. It appears that in a uraniferous granite such as this, conventional accuracy mineral suites probably cannot account for most of the uranium in the rock, and more rare, high U-concentration phases also are present and are significant uranium hosts. It appears that at least two different geological episodes have contributed to the disturbance of the U-Th-Pb isotope systems. Studies of various sites for transient dispersal of uranium, thorium, and radiogenic lead isotopes indicate a non-uniform dispersal of these components. It appears that the bulk rock has lost at least 24 percent of its original uranium endowment, accepting limited or no radiogenic lead or thorium migration from the sample.

  13. Geochemistry of late Cretaceous granitoids from northeastern Washington: implication for genesis of two-mica Cordilleran granites

    Energy Technology Data Exchange (ETDEWEB)

    Asmerom, Y.; Ikramuddin, M.; Kinart, K.

    1988-05-01

    Mesozoic two-mica granites and I-type granodiorites from northeastern Washington have initial /sup 87/Sr//sup 86/Sr ratios around 0.7100, similar to many other Cordilleran granitoids. Metapelite and calcsilicate country rocks, equivalent to the Belt Supergroup, have measured /sup 87/Sr//sup 86/Sr ratios in the range of 0.91 to 0.98. Unlike many of their Cordilleran counterparts, the northeastern Washington two-mica granites are enriched in U, Rb, and other incompatible elements, and therefore cannot have been derived from depleted lower crust sedimentary sources. Both the two-mica granites and the I-type granodiorites have similar rare-earth-element and trace-element enrichment patterns. Trace-elements modeling shows that it is feasible to derive the two-mica granites by 60% partial melting of a granodiorite-like source. The close association of Cordilleran metamorphic core complexes and older I-type granodiorites with two-mica granites supports this model.

  14. Experimental and theoretical study of the Nd:YAG laser removal of beeswax on Galician granite at 355 nm

    Science.gov (United States)

    Pan, Aldara; Rebollar, Esther; Conde, J. Carlos; Lusquiños, Fernando; Chiussi, Stefano; León, Betty

    2010-09-01

    Beeswax coatings applied to seal off the granitic surfaces of many monuments have resulted in detrimental effects with time passing. Conservation procedures must be carried out in a selective way, removing the beeswax without any degradation of the stone. In this study we present an experimental analysis of the removal of beeswax using a Nd:YAG laser at a wavelength of 355 nm which is absorbed weakly by the beeswax. For this reason, an important percentage of the laser radiation reaches the granite substrate and the influence of the layer thickness must be studied. At each laser fluence, for single-pulse irradiation we find a maximum thickness for complete removal of the film. For thicker layers, the beeswax is not removed and additional effects such as color changes and thickness increase are observed. The experimental results suggest that a photomechanical mechanism is dominant and that granite absorption plays a fundamental role. Multiple-pulse irradiation is also performed to determine the optimal parameters for laser cleaning. Finally, infrared thermography measurements allow for the determination of the granite surface temperature after laser irradiation and theoretical calculations allow one to estimate the absorption behavior of granite at 355 and to explain the results obtained.

  15. Comparative evaluation of UV-vis-IR Nd:YAG laser cleaning of beeswax layers on granite substrates

    Energy Technology Data Exchange (ETDEWEB)

    Pan, A., E-mail: aldarapan@uvigo.es [Departamento de Fisica Aplicada, E.T.S.I Industriales, Universidad de Vigo, Rua Maxwell s/n. Campus Universitario Lagoas-Marcosende, E-36310 Vigo (Spain); Chiussi, S.; Gonzalez, P.; Serra, J.; Leon, B. [Departamento de Fisica Aplicada, E.T.S.I Industriales, Universidad de Vigo, Rua Maxwell s/n. Campus Universitario Lagoas-Marcosende, E-36310 Vigo (Spain)

    2011-04-15

    The beeswax treatment applied in the sixties to prevent rain water from penetrating the outer stone surface of valuable granitic Galician monuments is contributing to the acceleration of the superficial degradation process of these monuments. At present, the northern sector of the renaissance frieze in the Cloister of the Cathedral of Santiago de Compostela is one of the most representative examples. Conventional wax removal methods (water, chemical and mechanical cleaning) can possibly destruct important details of the relief. Therefore laser removal is considered as a good alternative. In this work, we report systematic investigations of the effect of laser cleaning at different Nd:YAG laser wavelengths (266, 355, 532 and 1064 nm) on representative samples of the real historical surfaces. Laser removal of beeswax on granite at neither of the four wavelengths of the Nd:YAG laser is not a layer by layer removal process. For each irradiance and wavelength there is a maximum thickness that can be completely removed by a single pulse. Above this thickness the waxy material is not removed, although it undergoes thermal modifications; since the fraction of radiation that reaches the granite substrate is not enough to trigger the ejection of material. Our results show that the wax-granite interface plays a fundamental role in granite cleaning, and when the wax is weakened by absorption of radiation at 266 nm, the removal process becomes more efficient.

  16. Long Street: A Map of Post-Apartheid Cape Town

    Directory of Open Access Journals (Sweden)

    Giovanni Spissu

    2015-09-01

    Full Text Available No map fully coincides with the territory it represents. If the map and territory do not coincide, what can the map capture of the territory? According to Bateson, the answer is its differences. Drawing from Gregory Bateson’s ideas, we can envision an ethnographic representation of the city through which we can represent the urban territory through the different ways its inhabitants perceive it. In this article, I describe the process that led me to build a map of post-apartheid Cape Town from Long Street. I took inspiration from Bateson’s book Naven and compared it with the District Six Museum map in Cape Town with the objective of representing post-apartheid Cape Town through its differences.

  17. Phytogeography and speciation in the vegetation of the eastern Cape

    Directory of Open Access Journals (Sweden)

    G. E. Gibbs Russell

    1981-11-01

    Full Text Available The eastern Cape is a region of variable environmental factors, with a flora estimated at about 3 600 -4 000 species and encompassing 21 of Acocks’s (1975 veld types. It lies at the edges of the major phytochoria present in southern Africa, with many tropical species reaching the southern and western limits o f their distribution, and many south-western Cape and Karoo species reaching the northern and eastern limits of their distribution. The apparently low incidence o f species endemic to the eastern Cape may be the result of selection for ‘generalist’ genotypes and the close proximity of different phytochoria, which may allow species to migrate between phytochoria to fill niches resulting from environmental change.

  18. Delineation of Fractured Aquifer Using Numerical Analysis (Factor of Resistivity Data in a Granite Terrain

    Directory of Open Access Journals (Sweden)

    Rolland Andrade

    2014-01-01

    Full Text Available In hard rock terrain, fractured aquifers comprise the major source of groundwater availability where the phreatic aquifer is desaturated. Identification of fracture zones in hard rock terrain and potential groundwater source delineation had been a perennial problem in hydrology. The purpose of this paper is to highlight the study over a small watershed area, in a granite terrain, wherein an attempt was made to delineate and map the fractured aquifer using numerical (factor analysis of the conventional vertical electrical sounding data, which was obscure in curve matching technique. This numerical approach in concatenation with resistivity imaging or other techniques would prove to be an effective tool in groundwater exploration.

  19. Trace-element contents of postorogenic granites of the eastern Arabian Shield, Kingdom of Saudi Arabia

    Science.gov (United States)

    Stuckless, J.S.; Vaughn, R.B.; VanTrump, George

    1986-01-01

    Trace-element contents for 46 postorogenic granitoids vary by as much as two orders of magnitude; most samples are strongly enriched in incompatible elements (such as the heavy rare earths, yttrium, niobium, and uranium) and depleted in the compatible elements (such as barium, strontium, scandium, europium, and cobalt). These trace-element characteristics are typical of A-type granites found in other areas of the world. In spite of the wide range in trace-element contents, no samples contained economically significant concentrations of a single element.

  20. Petrogenesis of peralkaline granite dykes of the Straumsvola complex, western Dronning Maud Land, Antarctica

    Science.gov (United States)

    Harris, Chris; Dreyer, Tanya; le Roux, Petrus

    2018-01-01

    Peralkaline syenite and granite dykes cut the Straumsvola nepheline syenite pluton in Western Dronning Maud Land, Antarctica. The average peralkalinity index (PI = molecular Al/[Na + K]) of the dykes is 1.20 ( n = 29) and manifests itself in the presence of the Zr silicates eudialyte, dalyite and vlasovite, and the Na-Ti silicate, narsarsukite. The dykes appear to have intruded during slow cooling of the nepheline syenite pluton, and the petrogenetic relationship of the dykes and the pluton cannot be related to closed-system processes at low pressure, given the thermal divide that exists between silica-undersaturated and oversaturated magmas. Major and trace element variations in the dykes are consistent with a combination of fractional crystallization of parental peralkaline magma of quartz trachyte composition, and internal mineral segregation prior to final solidification. The distribution of accessory minerals is consistent with late-stage crystallization of isolated melt pockets. The dykes give an Rb-Sr isochron age of 171 ± 4.4 Ma, with variable initial 87Sr/86Sr ratio (0.7075 ± 0.0032), and have an average ɛ Nd of - 12.0. Quartz phenocrysts have δ18O values of 8.4-9.2‰, which are generally in O-isotope equilibrium with bulk rock. Differences in the δ18O values of quartz and aegirine (average Δquartz-aegirine = 3.5‰) suggest aegirine formation temperatures around 500 °C, lower than expected for a felsic magma, but consistent with poikilitic aegirine that indicates subsolidus growth. The negative ɛ Nd (values averaging 8.6‰ (assuming Δquartz-magma = 0.6‰) are inconsistent with a magma produced by closed-system fractional crystallization of a mantle-derived magma. By contrast, the nepheline syenite magma had mantle-like δ18O values and much less negative ɛ Nd (average - 3.1, n = 3). The country rock has similar δ18O values to the granite dykes (average 8.0‰, n = 108); this means that models for the petrogenesis of the granites by

  1. Characterization on the Fracture system in jurassic granitic rocks: Kosung and Yusung areas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Su; Bae, Dae Seok; Kim, Chun Soo; Park, Byung Yoon; Koh, Yong Kweon

    2001-03-01

    The safety of waste disposal can be achieved by a complete isolation of radioactive wastes from biosphere or by a retardation of nuclide migration to reach an acceptable dose level. For the deep geological disposal of high-level radioactive waste, the potential pathways of nuclide primarily depend on the spatial distribution characteristics of conductive fractures in rock mass. Major key issues in the quantification of fracture system for a disposal site are involved in classification criteria, hydraulic parameters, geometry, field investigation methods etc. This research aims to characterize the spatial distribution characteristics of regional lineaments and background fractures in eastern and western-type granite rock mass.

  2. Igneous origin of K-feldspar Megacrysts in Granitic Rocks of the Sierra Nevada Batholith

    Science.gov (United States)

    Moore, J. G.; Sisson, T. W.

    2007-12-01

    Study of the four principal K-feldspar megacrystic granitic plutons and related porphyrys in the Sierra Nevada composite batholith indicates that the included megacrysts are phenocrysts that grew in contact with granitic melt in long-lasting magma chambers. These 89-83 Ma plutons or intrusions are the youngest in the range, and represent the culminating magmatic phase of the batholith. They are the: Granodiorite of Topaz Lake; Cathedral Peak Granodiorite, Mono Creek Granite, Whitney Granodiorite, Johnson Granite Porphyry, and Golden Bear Dike. The zoned megacrysts in each of these igneous bodies attain 4-10 cm in length and all display oscillatory zoning with each zone beginning with a sharp increase followed by a gradual decrease in the concentration of BaO - commonly from 3 to 1 weight percent. Some of the more pronounced zones overlie resorption and channeling features on the underlying zone. Trains of small mineral inclusions (plagioclase, biotite, hornblende, quartz, sphene, and accessory minerals) are parallel to the BaO-delineated zones. The long axes of the inclusions are preferentially aligned parallel to the zone boundaries and inclusions are sorted by size from zone to zone. The growth temperature of sphene included in K-feldspar megacrysts is estimated by use of a Zr-in-sphene geothermometer. The sphene grains all yield igneous temperatures, mainly 735 - 760 °C. Sphene grains in the granodiorite host marginal to the megacrysts range to lower growth temperatures, in some instances into the subsolidus range. The zoning of the megacrysts, their presence in quenched porphry dikes, and the limited range and igneous values of growth temperatures of sphene inclusions within them, support the interpretation that the megacrysts formed as igneous sanidine phenocrysts, and that intrusion temperatures varied by only small amounts while the megacrysts grew. Each Ba- enriched zone was apparently formed by a repeated surge of new, hot melt injected into the large

  3. A study on the characteristics of site-scale fracture system in granite and volcanic rock

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Su; Kim, Chun Soo; Bae, Dae Seok; Park, Byoung Yoon; Koh, Young Kown [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    The safety of waste disposal can be achieved by a complete isolation of radioactive wastes from biosphere or by a retardation of nuclide migration to reach an acceptable dose level. For the deep geological disposal of high-level radioactive waste, the potential pathways of nuclide primarily depend on the spatial distribution characteristics of conductive fractures. Major key issues in the quantification of fracture system for a disposal site are involved in classification criteria, hydraulic parameters, geometry, field investigation methods etc. This research aims to characterize the spatial distribution characteristics of conductive fractures in granite and volcanic rock mass. 10 refs., 32 figs., 13 tabs. (Author)

  4. Drought Characteristics over the Western Cape Province, South Africa

    Directory of Open Access Journals (Sweden)

    Christina M. Botai

    2017-11-01

    Full Text Available Drought is a creeping phenomenon whose effects evolve with time, yet the start and end is often only clear in the hindsight. The present study assessed drought conditions using two categories of drought indicators computed from precipitation data sets measured by weather stations across the Western Cape Province, South Africa for the period 1985 to 2016. The first category was the Standardized Precipitation Index (SPI accumulated over 3-, 6- and 12-months (hereafter of SPI-3, SPI-6 and SPI-12 respectively. The second category consists of the four Drought Monitoring Indicators (DMI i.e., Drought Duration (DD, Severity (DS, Intensity (DI and Frequency (DF. Firstly, analysis of SPI-3, SPI-6 and SPI-12 illustrate that between 1985 and 2016, the Western Cape Province experienced recurrent mild drought conditions. This suggests that the drought conditions experienced during 2015/2016 hydrological year (hereafter current in the Western Cape Province is a manifestation of past drought conditions. Secondly, analysis of trends in DMI series depict a noticeable spatial-temporal dependence wherein the southern and western regions experienced more severe droughts compared to the eastern and northern regions of the Western Cape Province. Results also show that the DMI trends exhibit up to ~8% variability over the past decade. Overall, the current drought conditions in the Western Cape Province continues to adversely affect agricultural production while the water reservoirs are at below 30% capacity implying that the socio-economic impacts of these droughts will continue to reverberate for many months to come. Though the on-going drought conditions in the Western Cape Province is a regular part of nature’s cycle, analysis of historical drought characteristics based on drought indicators is an important first step towards placing the current drought conditions into perspective, and contribute to triggering action and response thereof. All these lay the

  5. Topography drives strong winds at Greenland's Cape Farewell

    Science.gov (United States)

    Schultz, Colin

    2013-02-01

    Jutting out into the northern Atlantic Ocean, the southernmost tip of Greenland—known as Cape Farewell—is the windiest oceanic site in the world, with gale-force winds whipping nearly a sixth of the time. The strong winds at Cape Farewell, called "tip jets," blow from both the east and the west. Along with another set of anomalously strong winds that blow along the country's southeast coast, the powerful flows are thought to have a strong effect on sea ice behavior, coastal ocean circulation patterns, the melt rate of Greenland's coastal glaciers, and North Atlantic deep ocean convection.

  6. Strategic analysis for the MER Cape Verde approach

    Science.gov (United States)

    Gaines, D.; Belluta, P.; Herman, J.; Hwang, P.; Mukai, R.; Porter, D.; Jones, B.; Wood, E.; Grotzinger, J.; Edgar, L.; Hayes, A.; Hare, T.; Squyres, S.

    2009-01-01

    The Mars Exploration Rover Opportunity has recently completed a two year campaign studying Victoria Crater. The campaign culminated in a close approach of Cape Verde in order to acquire high resolution imagery of the exposed stratigraphy in the cliff face. The close approach to Cape Verde provided significant challenges for every subsystem of the rover as the rover needed to traverse difficult, uncharacterised terrain and approach a cliff face with the potential of blocking out solar energy and communications with Earth. In this paper we describe the strategic analyses performed by the science and engineering teams so that we could successfully achieve the science objectives while keeping the rover safe. ??2009 IEEE.

  7. Strategic Analysis for the MER Cape Verde Approach

    Science.gov (United States)

    Gaines, Daniel; Belluta, Paolo; Herman, Jennifer; Hwang, Pauline; Mukai, Ryan; Porter, Dan; Jones, Byron; Wood, Eric; Grotzinger, John; Edgar, Lauren; hide

    2009-01-01

    The Mars Exploration Rover Opportunity has recently completed a two year campaign studying Victoria Crater. The campaign culminated in a close approach of Cape Verde in order to acquire high resolution imagery of the exposed stratigraphy in the cliff face. The close approach to Cape Verde provided significant challenges for every subsystem of the rover as the rover needed to traverse difficult, uncharacterised terrain and approach a cliff face with the potential of blocking out solar energy and communications with Earth. In this paper we describe the strategic analyses performed by the science and engineering teams so that we could successfully achieve the science objectives while keeping the rover safe.

  8. The effect of fulvic acid on the sorption of actinides and fission products on granite and selected minerals

    Energy Technology Data Exchange (ETDEWEB)

    Ticknor, K.V.; Vilks, P.; Vandergraaf, T.T. [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

    1996-07-01

    Organic material is present at low concentrations, typically 1-2mg/1 in terms of dissolved organic carbon (DOC), in groundwaters deep in granitic rock. Hydrophobic and hydrophilic acids may complex inorganic contaminants and change their sorption behaviour on geological materials. This report describes a series of experiments performed under aerobic conditions to investigate the effects of fulvic acid over a concentration range of 0-5 mg/1 DOC on the sorption of {sup 85}Sr, {sup 137}Cs, {sup 233}U, {sup 238}Pu and {sup 241}Am by crushed granite, biotite, goethite, montmorillonite and quartz. In addition, similar solutions were used to study the effects of dissolved fulvic acid on the sorption of {sup 99}Tc and {sup 125}I on each of the above solids except quartz. The fulvic acid was extracted from groundwater collected at a depth of 240 m in the granite rock of the Underground Research Laboratory near Lac du Bonnet, Manitoba. (Author).

  9. Distributed Gaussian basis sets : Variationally optimized s-type sets for H-2, LiH, and BH

    NARCIS (Netherlands)

    Glushkov, VN; Wilson, S

    2002-01-01

    Distributed basis sets of s-type Gaussian functions are determined by invoking the variation principle for the Hartree-Fock ground states of the H-2, LiH, and BH molecules at their respective experimental equilibrium geometries. The calculated energy expectation values supported by these finite

  10. A tetrapyridine ligand with a rigid tetrahedral core forms metal-organic frameworks with PtS type architecture.

    Science.gov (United States)

    Caputo, Christopher B; Vukotic, V Nicholas; Sirizzotti, Natalie M; Loeb, Stephen J

    2011-08-14

    A new tetradentate, pyridine ligand with a rigid tetrahedral core can be prepared in good yield by a cross-coupling methodology. Two metal organic framework structures of Cu(II) with PtS-type topology having a carbon atom as the tetrahedral node have been characterized utilising this ligand. This journal is © The Royal Society of Chemistry 2011

  11. Characterization of compression strength of granite-epoxy composites using design of experiments

    Directory of Open Access Journals (Sweden)

    Antonio Piratelli-Filho

    2008-12-01

    Full Text Available This paper presents a processing study of the polymer matrix composite (PMC developed with an epoxy polymeric matrix reinforced with particulate ceramic granite. This PMC composite has been reported to be used as structural parts of machine tools and Coordinate Measuring Machines due to its superior vibration damping characteristics and reduced processing cycle over cast iron. The investigated processing variables were epoxy content and particle size and the mechanical characterization was carried out by compressive tests. Rejects of granite with particle size smaller than 500 µm were prepared by crushing, milling and classification operations. The powder was mixed with different compositions of epoxy resin, between 15 and 20% in weight. An experiment was planned and executed according to the Factorial design technique using two variables at two levels. The obtained cylindrical samples were submitted to compressive strength tests and the results showed a maximum resistance of 114.23 MPa at 20 wt. (% epoxy, value close to that of the literature.

  12. Effect of limestone and granite coarse aggregate on drying shrinkage of a concrete

    Directory of Open Access Journals (Sweden)

    Woyciechowski Piotr

    2016-01-01

    Full Text Available In this paper the effect of limestone and granite aggregate on drying shrinkage of a concrete is investigated. Mixes containing limestone and granite with different Dmax and cement paste volume were tested. A two level, full factorial experiment with three independent factors was conducted which allowed not only to determine the influence of every single factor itself but also potential interactions between them. Measurements of shrinkage were performed up to 98 days after demolding on the beams (10×10×50 cm, in accordance with the procedure from polish standard PN-84/B-06714/23 (Amsler’s method. The multivariate analysis of variances (MANOVA was used for the statistical analysis of the results. The obtained results confirm that the cement paste volume has a decisive influence on a drying shrinkage of a concrete. However statistical analysis showed that with the assumed variability, either the Dmax or type of coarse aggregate has no significant influence on drying shrinkage, still those parameters may potentially be crucial in some cases. A statistically significant interaction between Dmax and type of aggregate has been found. Furthermore the results of drying shrinkage measurements were compared with estimation results from Bażant-Baweja B3 Model and Eurocode 2. The comparison shows that B3 Model provided more accurate results than Eurocode 2.

  13. Assessment of the Alteration of Granitic Rocks and its Influence on Alkalis Release

    Science.gov (United States)

    Ferraz, Ana Rita; Fernandes, Isabel; Soares, Dora; Santos Silva, António; Quinta-Ferreira, Mário

    2017-12-01

    Several concrete structures had shown signs of degradation some years after construction due to internal expansive reactions. Among these reactions there are the alkali-aggregate reactions (AAR) that occur between the aggregates and the concrete interstitial fluids which can be divided in two types: the alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR). The more common is the ASR which occurs when certain types of reactive silica are present in the aggregates. In consequence, an expansive alkali-silica gel is formed leading to the concrete cracking and degradation. Granites are rocks composed essentially of quartz, micas and feldspars, the latter being the minerals which contain more alkalis in their structure and thus, able to release them in conditions of high alkalinity. Although these aggregates are of slow reaction, some structures where they were applied show evidence of deterioration due to ASR some years or decades after the construction. In the present work, the possible contribution of granitic aggregates to the interstitial fluids of concrete by alkalis release was studied by performing chemical attack with NaOH and KOH solutions. Due to the heterogeneity of the quarries in what concerns the degree of alteration and/or fracturing, rock samples with different alteration were analysed. The alteration degree was characterized both under optical microscope and image analysis and compared with the results obtained from the chemical tests. It was concluded that natural alteration reduces dramatically the releasable alkalis available in the rocks.

  14. Early to Middle Devonian granitic and volcanic rocks from the central Gulf of Maine

    Science.gov (United States)

    Barr, Sandra M.; Mortensen, James K.; Thompson, Margaret D.; Hermes, O. Don; White, Chris E.

    2011-10-01

    Cashes Ledge igneous suite in the central Gulf of Maine is represented by 10 granitic and two felsic tuff samples collected from bedrock outcrops using the submersible Alvin in 1971-1972 and archived at the Woods Hole Oceanographic Institute. Laser ablation ICP-MS analyses of zircon grains yielded crystallization ages of 414.9 ± 1.1 Ma and 399.7 ± 1.5 Ma for two alkali feldspar granite samples, 407.0 ± 1.9 Ma for a syenogranite sample, and 384.4 ± 2.3 Ma and 383.9 ± 1.6 Ma for two felsic tuff samples. The samples contain iron-rich mafic minerals, including aegirine-augite, grunerite/ferroedenite, and annite. Most of the samples are alkaline to slightly peralkaline, with high concentrations of SiO 2, Y, Zr, Nb, and REE, strong negative Eu anomalies, and positive epsilon Nd values (1.8 to 3.7). The suite resembles part of a belt of similar Silurian-Devonian rocks with ages between 426 and 370 Ma now recognized in the central part of Avalonia in southeastern New England. They formed in a long-lived, likely extensional regime linked to subduction and subsequent complex transcurrent motions among Ganderia, Avalonia, and Meguma, culminating in the closure of the Rheic Ocean.

  15. Study on precursory characteristics of granite failure based on infrasonic energy

    Science.gov (United States)

    Wei, Jian-ping; Jia, Bing; Wen, Zhi-hui; Jia, Lin-xing

    To study signal characteristics of precursory infrasound of granite failure, coal-rock stress loading device and infrasound acquisition device were adopted to perform infrasound test in uniaxial loading process for granite samples. Wavelet filtering, infrasonic energy methods were used to process and analyze the test results. The results show that the infrasonic waves caused by the failure of rock samples are mainly in the middle and low frequency. Moreover, in the loading process, the ratio of relative energy of infrasound in different frequency sections and the total relative energy of the whole low frequency section both exhibit significant regularity of stage change, which is in consistent with the compaction stage, elastic stage, plastic stage of rock deformation. Additionally, the precursory characteristics of infrasound before rock failures are prominent and easy to be recognized. Meanwhile, infrasonic wave has the advantage of low attenuation in propagation process, which grants the superiority of infrasound prediction technology. A new method of rock failure prediction based on infrasound is formed, which provides an important reference for rock damage prediction in coal mining process.

  16. Lower Granite Dam Smolt Monitoring Program, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Mensik, Fred; Rapp, Shawn; Ross, Doug

    2004-08-01

    The 2003 fish collection season at Lower Granite Dam Juvenile Fish Facility (LGR) was characterized by water temperatures, total flows and spill that were below the five year average, low levels of debris, and increased smolt collection numbers compared to 2002 with the exception of unclipped sockeye/kokanee. There were 6,183,825 juvenile salmonids collected. Of these, 6,054,167 were transported to release sites below Bonneville Dam, 5,957,885 by barge and 96,282 by truck. An additional 102,340 fish were bypassed back to the river, primarily due to research projects with another 62,122 bypassed through the PIT-tag bypass system. According to the PTAGIS database, 152,268 PIT-tagged fish were detected at Lower Granite Dam. Of these, Smolt Monitoring Staff recorded 345 PIT-tagged raceway and sample mortalities. Of the 6,183,825 total fish collected, 113,290 were PIT-tagged or radio tagged and 380 were sacrificed by researchers. The collection included 836,885 fish that had hatchery marks other than clipped fins (elastomer, freeze brands or Coded Wire Tags). An estimated 54,857 incidental fish were collected with an additional 8,730 adult salmonids removed from the separator.

  17. Experimental and numerical study of drill bit drop tests on Kuru granite

    Science.gov (United States)

    Fourmeau, Marion; Kane, Alexandre; Hokka, Mikko

    2017-01-01

    This paper presents an experimental and numerical study of Kuru grey granite impacted with a seven-buttons drill bit mounted on an instrumented drop test machine. The force versus displacement curves during the impact, so-called bit-rock interaction (BRI) curves, were obtained using strain gauge measurements for two levels of impact energy. Moreover, the volume of removed rock after each drop test was evaluated by stereo-lithography (three-dimensional surface reconstruction). A modified version of the Holmquist-Johnson-Cook (MHJC) material model was calibrated using Kuru granite test results available from the literature. Numerical simulations of the single drop tests were carried out using the MHJC model available in the LS-DYNA explicit finite-element solver. The influence of the impact energy and additional confining pressure on the BRI curves and the volume of the removed rock is discussed. In addition, the influence of the rock surface shape before impact was evaluated using two different mesh geometries: a flat surface and a hyperbolic surface. The experimental and numerical results are compared and discussed in terms of drilling efficiency through the mechanical specific energy. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  18. Soil-gas radon monitoring in an active granite quarry from central Portugal

    Science.gov (United States)

    Pereira, A. J. S. C.; Barbosa, S. M.; Neves, L. J. P. F.; Aumento, F.

    2011-07-01

    Seven soil-gas radon monitoring stations were placed along the active front of a granite quarry in Canas de senhorim, Central Portugal, recording continuously for 81 days. Important differences in the radon concentration were found between stations, with average values comprised between 102 and 2982 Bq m-3, which can be explained by the local presence of uranium anomalies in the regional late-orogenic Hercynian granite, usually associated with faults. One of the boreholes exhibits large radon anomalies lasting for several days, and two, contrary to the others, show a clear daily periodic behaviour, with minima around 19:00 LT and maxima around 07:00 LT. The different patterns observed in stations placed at such a short distance (<100 m) has no clear explanation and deserves further investigation. Data analysis shows no evidence of soil-gas radon concentration changes during explosions carried out at the quarry. This is likely to result from the absence of a progressive stress field affecting the rock, as typically occurs before an earthquake.

  19. Soil-gas radon monitoring in an active granite quarry from central Portugal

    Directory of Open Access Journals (Sweden)

    A. J. S. C. Pereira

    2011-07-01

    Full Text Available Seven soil-gas radon monitoring stations were placed along the active front of a granite quarry in Canas de senhorim, Central Portugal, recording continuously for 81 days. Important differences in the radon concentration were found between stations, with average values comprised between 102 and 2982 Bq m−3, which can be explained by the local presence of uranium anomalies in the regional late-orogenic Hercynian granite, usually associated with faults. One of the boreholes exhibits large radon anomalies lasting for several days, and two, contrary to the others, show a clear daily periodic behaviour, with minima around 19:00 LT and maxima around 07:00 LT. The different patterns observed in stations placed at such a short distance (<100 m has no clear explanation and deserves further investigation. Data analysis shows no evidence of soil-gas radon concentration changes during explosions carried out at the quarry. This is likely to result from the absence of a progressive stress field affecting the rock, as typically occurs before an earthquake.

  20. Estimation of sedimentation rates based on the excess of radium 228 in granitic reservoir sediments.

    Science.gov (United States)

    Reyss, Jean-Louis; Mangeret, Arnaud; Courbet, Christelle; Bassot, Sylvain; Alcalde, Gilles; Thouvenot, Antoine; Guillevic, Jérôme

    2016-10-01

    Knowledge of sedimentation rates in lakes is required to understand and quantify the geochemical processes involved in scavenging and remobilization of contaminants at the Sediment-Water Interface (SWI). The well-known 210Pb excess (210Pbex) method cannot be used for quantifying sedimentation rates in uranium-enriched catchments, as large amounts of 210Pb produced by weathering and human activities may dilute the atmospheric 210Pb. As an alternative dating method in these cases, we propose an original method based on 232Th decay series nuclides. This study focuses on an artificial lake located in a granitic catchment downstream from a former uranium mine site. The exponential decay of 228Ra excess (228Raex) with depth in two long cores yields sedimentation rates of 2.4 and 5.2 cm yr-1 respectively. These sedimentation rates lead to the attribution of the 137Cs activity peak observed at depth to the Chernobyl fallout event of 1986. The 228Raex method was also applied to two short cores which did not display the 137Cs peak, and mean sedimentation rates of 2.1 and 4.0 cm y-1 were deduced. The proposed method may replace the classical radiochronological methods (210Pbex, 137Cs) to determine sedimentation rates in granitic catchments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Radioelement distributions in the Proterozoic granites and associated pegmatites of Gabal El Fereyid area, Southeastern Desert, Egypt.

    Science.gov (United States)

    Abd El-Naby, H H; Saleh, G M

    2003-10-01

    Lithologically, the rock types in the Gabal El Fereyid area are dominantly granites with minor amounts of pegmatites. The granites range in composition from tonalite to granite-adamallite with minor acidic dikes, quartz and pegmatite veins. The granite-adamallite is peraluminous and formed as a result of partial melting of amphibole-bearing rocks at depths of approximately 24-30 km and at temperatures of 800-950 degrees C. Among the different rock types, the muscovite-rich pegmatites had the highest U and Th contents (66 and 38 ppm on average, respectively). The high level of radioactivity in pegmatites is attributed to the presence of the radioactive minerals thorianite, uranophane and allanite as confirmed by XRD analysis. Binary relations of Zr/U, Zr/Th, Ce/U and Ce/Th against either U or Th in the granite-adamellite exhibit significant negative correlations indicating that both elements are not preferentially hosted in the accessory minerals phases such as zircon and monazite, but could be associated with major forming minerals such as biotite, muscovite, plagioclase and quartz, or U is situated within labile sites within granite. The uranium and thorium enrichment in the pegmatites is a two-stage process. The primary stage is magmatic whereas the secondary enrichment is from hydrothermal concentration. The magmatic U and Th are indicated by the presence of thorianite and allanite, whereas evidence of hydrothermal mineralization is the alteration of rock-forming minerals such as feldspar and the formation of secondary minerals such as uranophane and pyrite.

  2. Newly discovered uranium mineralization at 2.0 Ma in the Menggongjie granite-hosted uranium deposit, South China

    Science.gov (United States)

    Luo, Jin-Cheng; Hu, Rui-Zhong; Fayek, Mostafa; Bi, Xian-Wu; Shi, Shao-Hua; Chen, You-Wei

    2017-04-01

    The southeastern part of the Nanling metallogenic province, South China contains numerous economically important granite-hosted, hydrothermal vein-type uranium deposits. The Miao'ershan (MES) uranium ore field is one of the most important uranium sources in China, hosts the largest Chanziping carbonaceous-siliceous-pelitic rock-type uranium deposit and several representative granite-hosted uranium deposits. The geology and geochemistry of these deposits have been extensively studied. However, accurate and precise ages for the uranium mineralization are scarce because uranium minerals in these deposits are usually fine-grained, and may have formed in several stages, thus hindering the understanding of the uranium metallogenesis of this province. The Menggongjie (MGJ) uranium deposit is one of the largest granite-hosted uranium deposits in the MES ore field. Uranium mineralization in this deposit occurs at the central part of the MES granitic complex, accompanied with silicification, fluorination, K-metasomatism and hematitization. The ore minerals are dominated by uraninite, occurring in quartz or fluorite veinlets along fractures in altered granite. In-situ SIMS U-Pb dating on the uraninite yields the U-Pb isotopic age of 1.9 ± 0.7 Ma, which is comparable to the chemical U-Th-Pbtol uraninite age of 2.3 ± 0.1 Ma. Such ages agree well with the eruption ages of the extension-related Quaternary volcanics (2.1-1.2 Ma) in South China, suggesting that the uranium mineralization have formed at an extensional setting, possibly related to the Quaternary volcanic activities. Therefore, our robust, new dating results of the MGJ uranium deposit make it the youngest granite-hosted uranium deposit reported so far in South China and the mineralization event represents a newly identified mineralization epoch.

  3. Zircon dating and mineralogy of the Mokong Pan-African magmatic epidote-bearing granite (North Cameroon)

    Science.gov (United States)

    Tchameni, R.; Sun, F.; Dawaï, D.; Danra, G.; Tékoum, L.; Nomo Negue, E.; Vanderhaeghe, O.; Nzolang, C.; Dagwaï, Nguihdama

    2016-09-01

    We present the mineralogy and age of the magmatic epidote-bearing granite composing most of the Mokong pluton, in the Central Africa orogenic belt (North Cameroon). This pluton intrudes Neoproterozoic (~830 to 700 Ma) low- to high-grade schists and gneisses (Poli-Maroua group), and is crosscut or interleaved with bodies of biotite granite of various sizes. The pluton is weakly deformed in its interior, but solid-state deformation increases toward its margins marked by narrow mylonitic bands trending NNE-SSW. The magmatic epidote granitic rocks are classified as quartz monzodiorite, granodiorite, monzogranite, and syenogranite. They are medium- to coarse-grained and composed of K-feldspar + plagioclase + biotite + amphibole + epidote + magnetite + titanite + zircon + apatite. In these granites, the pistacite component [atomic Fe+3/(Fe3+ + Al)] in epidote ranges from 16 to 29 %. High oxygen fugacity (log ƒO2 - 14 to -11) and the preservation of epidote suggest that the magma was oxidized. Al-in hornblende barometry and hornblende-plagioclase thermometry indicate hornblende crystallization between 0.53 and 0.78 GPa at a temperature ranging from 633 to 779 °C. Zircon saturation thermometry gives temperature estimates ranging from 504 to 916 °C, the latter being obtained on samples containing inherited zircons. U/Pb geochronology by LA-ICP-MS on zircon grains characterized by magmatic zoning yields a concordia age of 668 ± 11 Ma (2 σ). The Mokong granite is the only known occurrence magmatic epidote in Cameroon, and is an important milestone for the comparison of the Central Africa orogenic belt with the Brasiliano Fold Belt, where such granites are much more abundant.

  4. S-type and P-type habitability in stellar binary systems: A comprehensive approach. I. Method and applications

    Energy Technology Data Exchange (ETDEWEB)

    Cuntz, M., E-mail: cuntz@uta.edu [Department of Physics, University of Texas at Arlington, Arlington, TX 76019-0059 (United States)

    2014-01-01

    A comprehensive approach is provided for the study of both S-type and P-type habitability in stellar binary systems, which in principle can also be expanded to systems of higher order. P-type orbits occur when the planet orbits both binary components, whereas in the case of S-type orbits, the planet orbits only one of the binary components with the second component considered a perturbator. The selected approach encapsulates a variety of different aspects, which include: (1) the consideration of a joint constraint, including orbital stability and a habitable region for a putative system planet through the stellar radiative energy fluxes ({sup r}adiative habitable zone{sup ;} RHZ), needs to be met; (2) the treatment of conservative, general, and extended zones of habitability for the various systems as defined for the solar system and beyond; (3) the provision of a combined formalism for the assessment of both S-type and P-type habitability; in particular, mathematical criteria are presented for the kind of system in which S-type and P-type habitability is realized; (4) applications of the attained theoretical approach to standard (theoretical) main-sequence stars. In principle, five different cases of habitability are identified, which are S-type and P-type habitability provided by the full extent of the RHZs; habitability, where the RHZs are truncated by the additional constraint of planetary orbital stability (referred to as ST- and PT-type, respectively); and cases of no habitability at all. Regarding the treatment of planetary orbital stability, we utilize the formulae of Holman and Wiegert as also used in previous studies. In this work, we focus on binary systems in circular orbits. Future applications will also consider binary systems in elliptical orbits and provide thorough comparisons to other methods and results given in the literature.

  5. Evolution of C, D and S-type cystatins in mammals: an extensive gene duplication in primates.

    Science.gov (United States)

    de Sousa-Pereira, Patrícia; Abrantes, Joana; Pinheiro, Ana; Colaço, Bruno; Vitorino, Rui; Esteves, Pedro J

    2014-01-01

    Cystatins are a family of inhibitors of cysteine peptidases that comprises the salivary cystatins (D and S-type cystatins) and cystatin C. These cystatins are encoded by a multigene family (CST3, CST5, CST4, CST1 and CST2) organized in tandem in the human genome. Their presence and functional importance in human saliva has been reported, however the distribution of these proteins in other mammals is still unclear. Here, we performed a proteomic analysis of the saliva of several mammals and studied the evolution of this multigene family. The proteomic analysis detected S-type cystatins (S, SA, and SN) in human saliva and cystatin D in rat saliva. The evolutionary analysis showed that the cystatin C encoding gene is present in species of the most representative mammalian groups, i.e. Artiodactyla, Rodentia, Lagomorpha, Carnivora and Primates. On the other hand, D and S-type cystatins are mainly retrieved from Primates, and especially the evolution of S-type cystatins seems to be a dynamic process as seen in Pongo abelii genome where several copies of CST1-like gene (cystatin SN) were found. In Rodents, a group of cystatins previously identified as D and S has also evolved. Despite the high divergence of the amino acid sequence, their position in the phylogenetic tree and their genome organization suggests a common origin with those of the Primates. These results suggest that the D and S type cystatins have emerged before the mammalian radiation and were retained only in Primates and Rodents. Although the mechanisms driving the evolution of cystatins are unknown, it seems to be a dynamic process with several gene duplications evolving according to the birth-and-death model of evolution. The factors that led to the appearance of a group of saliva-specific cystatins in Primates and its rapid evolution remain undetermined, but may be associated with an adaptive advantage.

  6. The effect of surface finishes on outdoor granite and limestone pavers

    Directory of Open Access Journals (Sweden)

    Martínez-Martínez, J.

    2008-06-01

    Full Text Available Two types of ornamental stones, namely granite (Blanco Rafaela or Zarzalejo Granite and microcrystalline limestone (marble known commercially as Gris Pulpis, treated for different surface finishes, were tested for suitability as paving slabs. The finishes tested in both stones were polishing, hammering, honing and flaming, while acid treatment and abrasion were applied to limestone only and sawn finishes were only studied in granite.The stones were tested for the three physical properties that determine suitability for use as paving slabs; flexural strength under a concentrated load, and abrasion and slip resistance. Laboratory freeze-thaw cycle ageing tests were also conducted and flexural strength subsequently evaluated. Stone water sorption proved to be substantially unaltered by the type of finish employed. Finish barely affected flexural strength, except in the case of limestone flaming, where it was lower. Hammering was found to provide good slip resistance in both stones. The best slip performance for granite, however, was found for flamed specimens. Finish was shown to have no effect on abrasion resistance in either of the stone materials. Polished limestone suffered the least damage in freeze-thaw cycles, whereas freeze-thaw resistance was similar in all the granite specimens, regardless of the finish used.Se han estudiado, para su utilización como baldosas de pavimentos, granito (Blanco Rafaela o Granito de Zarzalejo y caliza microcristalina (mármol comercial Gris Pulpis con diferentes acabados. Estos acabados son: pulido, apomazado, abujardado y flameado en ambas rocas y además acabado al ácido y amolado en la caliza. Se han determinado mediante ensayos estandarizados las tres propiedades físicas de mayor interés para el uso de la piedra natural como baldosa en pavimentos de exteriores: resistencia a la flexión bajo carga concentrada, a la abrasión y al deslizamiento. Se han realizado ensayos de durabilidad por ciclos de hielo

  7. Emplacement mechanisms and structural influences of a younger granite intrusion into older wall rocks - a principal study with application to the Goetemar and Uthammar granites. Site-descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Cruden, Alexander R. (Dept. of Geology, Univ. of Toronto (Canada))

    2008-12-15

    The c. 1.80 Ga old bedrock in the Laxemar-Simpevarp area, which is the focus of the site investigation at Oskarshamn, is dominated by intrusive rocks belonging to the c. 1.86-1.65 Ga Transscandinavian Igneous Belt (TIB). However, the site investigation area is situated in between two c. 1.45 Ga old anorogenic granites, the Goetemar granite in the north and the Uthammar granite in the south. This study evaluates the emplacement mechanism of these intrusions and their structural influence on the older bedrock. Field observations and structural measurements indicate that both the Goetemar and the Uthammar granites are discordant and have not imposed any significant ductile deformation on their wall-rocks. The apparent conformity of geological contacts and fabrics in the wall rocks and the southern margin of the Goetemar granite is coincidental and inherited from the pattern of Svecokarelian deformation of the TIB. However, interpretation of regional aeromagnetic data suggests that the granites occur within a broad, NNE-SSW trending linear belt, pointing to deep seated tectonic control on their generation, ascent and emplacement. Thermochronology indicates that the granites were emplaced at depths between 4 and 8 km into brittle wall rocks. The 3-D shape of the Goetemar and Uthammar plutons has been investigated by 2.75D forward modelling of the residual gravity anomalies due to both granites. Both granites are associated with strong residual gravity anomalies of up to -10 mgal. Constraints on the geometry of the plutons at the surface are provided from surface geology maps and several deep boreholes located on or close to the model profiles. A further variable in the gravity modelling is introduced by either allowing the upper contact of the plutons to assume the most suitable orientation to produce the best fit between the modelled and observed gravity ('unconstrained models') or by forcing the near surface orientation of the contacts to be vertical (&apos

  8. The Early Jurassic Bokan Mountain peralkaline granitic complex (southeastern Alaska): geochemistry, petrogenesis and rare-metal mineralization

    Science.gov (United States)

    Dostal, Jaroslav; Kontak, Daniel J.; Karl, Susan M.

    2014-01-01

    The Early Jurassic (ca. 177 Ma) Bokan Mountain granitic complex, located on southern Prince of Wales Island, southernmost Alaska, cross-cuts Paleozoic igneous and metasedimentary rocks of the Alexander terrane of the North American Cordillera and was emplaced during a rifting event. The complex is a circular body (~3 km in diameter) of peralkaline granitic composition that has a core of arfvedsonite granite surrounded by aegirine granite. All the rock-forming minerals typically record a two-stage growth history and aegirine and arfvedsonite were the last major phases to crystalize from the magma. The Bokan granites and related dikes have SiO2 from 72 to 78 wt. %, high iron (FeO (tot) ~3-4.5 wt. %) and alkali (8-10 wt.%) concentrations with high FeO(tot)/(FeO(tot)+MgO) ratios (typically >0.95) and the molar Al2O3/(Na2O+K2O) ratio Nd values which are indicative of a mantle signature. The parent magma is inferred to be derived from an earlier metasomatized lithospheric mantle by low degrees of partial melting and generated the Bokan granitic melt through extensive fractional crystallization. The Bokan complex hosts significant rare-metal (REE, Y, U, Th, Nb) mineralization that is related to the late-stage crystallization history of the complex which involved the overlap of emplacement of felsic dikes, including pegmatite bodies, and generation of orthomagmatic fluids. The abundances of REE, HFSE, U and Th as well as Pb and Nd isotopic values of the pluton and dikes were modified by orthomagmatic hydrothermal fluids highly enriched in the strongly incompatible trace elements, which also escaped along zones of structural weakness to generate rare-metal mineralization. The latter was deposited in two stages: the first relates to the latest stage of magma emplacement and is associated with felsic dikes that intruded along the faults and shear deformations, whereas the second stage involved ingress of hydrothermal fluids that both remobilized and enriched the initial

  9. Predictors of Psychological Adaptation of Cape Verdean Students in Portugal

    Science.gov (United States)

    Neto, Félix; Wilks, Daniela C.

    2017-01-01

    We examined the predictors of psychological adaptation regarding subjective well-being and loneliness among international students. The sample included 243 Cape Verdean students attending Portuguese universities, and the control group was composed by 265 native-born Portuguese students. The latter group reported higher levels of well-being and…

  10. Temporality and Patterns of ART Adherence in the Western Cape

    African Journals Online (AJOL)

    In an ethnographic study conducted over thirty months in South Africa's Western Cape Province ending in 2012, we explored ART adherence amongst almost 200 patients attending three clinics. This setting contained significant political, structural, economic and socio cultural barriers to the uptake of, and adherence to, ...

  11. Apparent survival rates of Cape Sugarbirds Promerops cafer at a ...

    African Journals Online (AJOL)

    Reliable estimates of survival rates of southern African bird species are still rare. Yet precise information on life history traits of birds from this southern Mediterranean-type climate would help in evaluating the generality of global patterns of avian life history. We estimated annual survival of Cape Sugarbirds Promerops cafer ...

  12. EAARL Coastal Topography–Cape Cod National Seashore, Massachusetts, 2002

    Science.gov (United States)

    Kranenburg, Christine; Hardy, Matthew; Nagle, David B.

    2017-01-01

    These datasets, prepared by the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in collaboration with the National Park Service, provide lidar-derived first-surface and bare-earth topography for Cape Cod National Seashore, Massachusetts. Elevation measurements were acquired by the Experimental Advanced Airborne Research Lidar (EAARL) during October 2002.

  13. Reproductive biology of the cape serotine bat, Eptesicus capensis in ...

    African Journals Online (AJOL)

    The reproductive biology of the Cape serotine bat, Eptesicus capensis, was investigated histologically. The study was based on 67 specimens collected over a six-year period. This species is seasonally monoestrous, normally giving birth to twins during November. Spermatogenesis peaks during autumn (March-May) when ...

  14. Vulnerability and Poverty Dynamics in Rural Areas of Eastern Cape ...

    African Journals Online (AJOL)

    If the aim of studying poverty is not only improving the well-being of households who are currently poor, but also preventing people from becoming poor in the future, a new forward looking perspective must be adopted. This study analyses determinants of household poverty dynamics in rural areas of the Eastern Cape ...

  15. Determinants of terrestrial arthropod community composition at Cape Hallett, Antarctica

    CSIR Research Space (South Africa)

    Sinclair, BJ

    2006-09-01

    Full Text Available The distribution and abundance of free-living arthropods from soil and under stones were surveyed at the Cape Hallett ice-free area (ASPA No. 106), North Victoria Land, Antarctica. A total of 327 samples from 67 plots yielded 11 species...

  16. Urban Ecology in Cape Town: South African Comparisons and Reflections

    Directory of Open Access Journals (Sweden)

    Sarel S. Cilliers

    2012-09-01

    Full Text Available Little urban ecological research has been done in South Africa. The papers in the Ecology and Society special feature Urban Ecological and Social-Ecological Research in the City of Cape Town make, therefore, an important contribution to the development of urban ecology locally and globally. Different approaches have been used in the study of urban ecology of different urban areas in South Africa. Cape Town is situated in a biodiversity hotspot and is the only South African city which includes a national park. As a result the urban ecological studies were mainly driven by urban nature conservation concerns. In other cities such as Durban, open space planning and environmental management were the major issues which focused ecological studies on urban areas whereas other studies of urban areas in the Eastern Cape and North-West provinces included private and public open spaces and man-made habitats. We reflect on the Cape Town studies in a South African context and highlight conservation of biodiversity, protection of ecosystem services, management of control measures, and the conflict between humans and nature. A brief synthesis has also been given of South African urban ecological research in general.

  17. Digestive parameters and energy assimilation of Cape porcupine on ...

    African Journals Online (AJOL)

    Digestive parameters and energy assimilation of Cape porcupine on ... body mass on all three experimental diets and energy intake ranged from 3 002.36 kJ kg−1 ... Keywords: agricultural pest, assimilation, digestion, human–wildlife conflict, ...

  18. Potable water use of residential consumers in the Cape Town ...

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... process for supplementary on-site water sources that was introduced by the City of Cape Town during the prolonged drought between 2004 and 2005. The main objective of this research was to determine the average annual water demand of residential properties serviced via the potable water distribution ...

  19. Estimating Cape hare occupancy and abundance in southern ...

    African Journals Online (AJOL)

    This study outlines the importance of integrating spotlighting data and occupancy modelling to estimate the spatial occupancy, abundance and habitat preferences of Cape hares Lepus capensis in southern Tunisia. Exploring the spatial distribution pattern of this species is problematic because of its nocturnal and secretive ...

  20. Inflammatory bowel disease Cape Town, 1975-1980

    African Journals Online (AJOL)

    1983-02-12

    Feb 12, 1983 ... SA MEDIESE TYDSKRIF DEEL 63 12 FEBRUARIE 1983. 3. Tobias R, Wright JP, Konler RE et al. Primary sclerosing cholangitis asso- ciated with inflammatory bowel disease in Cape Town, 197;"'1981. S. Afr Med] 1983; 63: 229-235. 4. Edwards Fe, Truelove Se. The course and prognosis ofulcerative colitis ...

  1. New ways to deal with Cape Town's flooded communities | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Others, like Bomkazi Sokhaya, live with sewage-tainted water seeping into their homes. The municipality's portable toilets aren't emptied regularly, leaving many residents to use buckets as toilets, which they empty into the standing water near Sokhaya's home. The Cape Flats' challenges won't simply go away. Climate ...

  2. Fifteen years of annual Cape Parrot Poicephalus robustus censuses ...

    African Journals Online (AJOL)

    The Cape Parrot Poicephalus robustus is endemic to South Africa and numbers have reportedly declined since the early 1900s. It is a forest specialist and food nomadic, moving between patches depending on fruit availability. This makes it difficult to estimate numbers accurately and to determine its distribution. The annual ...

  3. Observations of Cape Parrot, Poicephalus robustus, nesting in the wild

    African Journals Online (AJOL)

    standing dead trees) making monitoring of nest contents and nest activities difficult and dangerous. Here the breeding activity of a Cape Parrot pair in the cavity of a live Henkell\\'s Yellowwood (Podocarpus henkellii) is presented. Four eggs were ...

  4. Abundance of the endangered Cape parrot, Poicephalus robustus ...

    African Journals Online (AJOL)

    Factors affecting the decline of the endangered Cape parrot, which is endemic to South Africa, are presented. Its abundance and status were investigated during annual intensive national surveys. The merits of such a census are reported. Presence of birds was unpredictable at forest patches throughout its range. Present ...

  5. Abundance and activity patterns of the Cape parrot ( Poicephalus ...

    African Journals Online (AJOL)

    Behaviour, movements and numbers of the rare Cape parrot (Poicephalus robustus) were investigated at two study sites to assess its conservation status and as the basis for an action plan for their conservation. Birds flew regularly to and from nearby forests and were observed arriving at a feeding site (Hlabeni) from ...

  6. Agrichemical safety practices on farms in the western Cape | London ...

    African Journals Online (AJOL)

    In order to study agrichemical safety practices in a rural farming area in the western Cape, an audit of 45 randomly sampled farms was performed over 3 months in 1992. A response rate of 87% was achieved, and the survey results suggest that approximately 9% of permanent and 14% of seasonal farm workers are ...

  7. Composition of commercial Cape chamomile oil (Eriocephalus punctualus)

    NARCIS (Netherlands)

    Mierendorff, H.G.; Stahl-Biskup, E.; Posthumus, M.A.; Beek, van T.A.

    2003-01-01

    Cape chamomile oil obtained from the herb Eriocephalus punctulatus DC (Asteraceae) was analysed by GC and GC–MS. It was shown to consist of about 50 aliphatic esters, together amounting to more than 50% of the oil. 2-Methylbutyl 2-methylpropanoate (21.2%), 2-methylbutyl 2-methylbutanoate (5.6%),

  8. Tourism Policies and the Space Economy of the Eastern Cape ...

    African Journals Online (AJOL)

    Tourism Policies and the Space Economy of the Eastern Cape Province of South Africa: A Critical Realist Perspective. ... African Journal for Physical Activity and Health Sciences ... Other instruments such as the Tourism Black Economic Empowerment (BEE) Charter also exist to implement BEE in the tourism industry.

  9. Observations of microtrash ingestion in Cape Vultures in the Eastern ...

    African Journals Online (AJOL)

    Two pieces of microtrash were collected from the nest of another nestling. Neither nestling appeared to have skeletal deformities or feather stress bars. Our results highlight the persistence of microtrash ingestion by Cape Vulture nestlings, which could impact the species negatively. Keywords: conservation, nestling, trash, ...

  10. Valuing water gains in the Eastern Cape's Working for Water ...

    African Journals Online (AJOL)

    A procedure for pricing water is described and applied in six WWP projects in the Eastern Cape province: Tsitsikamma, Kouga, Port Elizabeth Driftsands, Albany, Balfour and Pott River. It is shown that the procedure yields very different prices at the different sites, and higher prices for projects that increase river flows feeding ...

  11. Mapping Soil Erosion in a Quaternary Catchment in Eastern Cape ...

    African Journals Online (AJOL)

    Temp

    2017-04-06

    Apr 6, 2017 ... Mapping Soil Erosion in a Quaternary Catchment in Eastern Cape. Using Geographic Information System and Remote Sensing. Kwanele Phinziª ⃰, Njoya Silas Ngetarª. ªSchool of Agricultural, Earth and Environmental Sciences, Discipline of Geography, University of. KwaZulu-Natal, Durban, South Africa.

  12. The Cape horse mackerel Trachurus trachurus capensis is the most ...

    African Journals Online (AJOL)

    denise

    vessels (Table III). Therefore, more fish, especially larger active fish, would be expected to escape from the front of the research vessel's net. The behaviour of horse mackerel in reaction to the trawl plays an important role in their capture. Cape horse mackerel Trachurus t. capensis reacted to nets by diving, shown by a drop ...

  13. A critical appraisal of Western Cape Forum for Intellectual Disability ...

    African Journals Online (AJOL)

    Canada's similar conception of equality and India's influence on South African constitutionalism and shared experience with massive equality gaps make these jurisdictions instructive. Keywords: disability; Western Cape Forum for Intellectual Disability v Government of The Republic of South Africa; substantive equality; ...

  14. Health care achievement and challenges in the Western Cape

    African Journals Online (AJOL)

    hail u yers die s e tinson tifor r bs zler dat oub icroft der Spuy ensburg son s. Issues in. Medicine. Health care achievement and challenges in the. Western Cape. The health sector in the country and in the province has probably delivered most to the expectations of the mass of our citizens: (I) the introduction of free primary ...

  15. The 1992 tneasles epidetnic in Cape Town - a changing ...

    African Journals Online (AJOL)

    Measles is most prevalent in developing countries, where it is ... country-wide decline in measles notifications has been noted. This could be .... ed by means of the relative risk ratio.IQ Categorical data were evaluated by the x2-test and continuous data by the. Kruskall-Wallis test. Cape Town epidemic. Fig. 1 shows the ...

  16. A student surgical society – the Cape Town experience | Favara ...

    African Journals Online (AJOL)

    managed academic society that promotes undergraduate interest in the field of surgery at the University of Cape Town. With over 700 members in 2009, it is one of the largest student surgical societies in the world. This article describes the origins, ...

  17. Yersinia enterocolitica in the Western Cape | Finlayson | South ...

    African Journals Online (AJOL)

    Yersinia enterocolitica, serotype 3, phage type 9a, has been isolated for the first time in the Western Cape. Sera from 59 abattoir workers were investigated for the presence of 0 and H agglutinins. These were present in one sample, suggesting a past infection. Sera from 115 Nama-speaking adults of the Kuboes area ...

  18. Optimising school-based health promotion in the Western Cape ...

    African Journals Online (AJOL)

    Background. Recent evaluation of the Interdisciplinary Health Promotion (IHP) course offered by the University of the Western Cape (UWC) at schools revealed that the needs expressed by the schools had not changed in the last five years. Objectives. This paper describes the process that was undertaken to identify specific ...

  19. Integrated water resource planning in the city of Cape Town

    African Journals Online (AJOL)

    driniev

    Accordingly, a Water Demand Management Section was formed in the Water Department of the former Cape Metropolitan Council. (CMC). This section .... in the urban and agricultural sectors be allowed to grow unre- stricted, it would not .... public. In a joint venture with the Catchment, River and Stormwater. Management ...

  20. New ways to deal with Cape Town's flooded communities | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2013-12-03

    Dec 3, 2013 ... Even in the formally housed areas, where the wetland has been tarred over and cemented in, stormwater drains back up: debris and household waste then ... The City of Cape Town is also working to develop a rigorous coastal policy and management framework to better respond to the pressures of urban ...

  1. 1Department of Psychiatry, University of Stellenbosch, Cape Town ...

    African Journals Online (AJOL)

    Mexico, Albuquerque, USA. 4Department of Nutrition, Gillings School of Global Public Health, the University of. North Carolina, Chapel Hill, USA. ABStrAct. Foetal Alcohol Syndrome (FAS) has been identified as among the most serious consequences associated with hazardous and harmful drinking in the Western Cape ...

  2. THE ECOLOGY OF PATELLA LINNAEUS FROM THE CAPE ...

    African Journals Online (AJOL)

    (Evans 1947, Das and Sesheppa 1948 and Lewis 1964) and New Zealand with two species of eellana (Morton and Miller 1968). The coast of America is lacking in .... Peninsula. This geographical limitation excludes only one South African species, P. l'arlllbilis, which occurs only as far south as Cape Padrone (Fig. 1).

  3. role of stakeholders at cape coast ppag youth centre

    African Journals Online (AJOL)

    Elizabeth

    consensus by the stakeholders that visitations to the Cape Coast PPAG youth centre were very poor and ... organised for all stakeholders to enlighten them on the need to intensify their efforts to make more people aware of ... is to strengthen this position by constantly organising educative but inspiring messages for the ...

  4. Validating homicide rates in the Western Cape Province, South Africa

    African Journals Online (AJOL)

    homicide rate of 85/100 000 in the province was approximately 1.8 times the national average,[3] albeit based on crude rates that did not account for provincial differences in the age profile. SAPS data suggest that there has been a significant decline in homicide rates in the Western Cape relative to other provinces since.

  5. Dusky dolphins Lagenorhynchus obscurus and Cape fur seals ...

    African Journals Online (AJOL)

    The fatty acid composition of the blubber of five dusky dolphins Lagenorhynchus obscurus and five Cape fur seals Arctocephalus pusillus pusillus from the northern Benguela ecosystem (South-East Atlantic) and their main prey was determined. Differences in fatty acid composition of the inner and outer blubber layer of the ...

  6. Hypertension care at a Cape Town community health centre | Lunt ...

    African Journals Online (AJOL)

    Objectives. To describe the demographic profile of hypertensive patients and the quality of care for hypertension at a Cape Town community health centre (CHC). Design. Prospective, descriptive study. Setting and subjects. Medium-sized CHC, attended by 1098 hypertensive patients during a 1-year period from 1 January ...

  7. Aggressive behaviour of an adult male Cape fur seal ...

    African Journals Online (AJOL)

    This is a report of a marine predator (the white shark) being threatened by a member of the species on which it preys (a male Cape fur seal). Although these events may be rarely observed or occur infrequently, they may have important implications for the predator and its prey.We suggest that shark mobbing by adult male ...

  8. Trophic structure and biomass distribution on two East Cape rocky ...

    African Journals Online (AJOL)

    1980-01-12

    Jan 12, 1980 ... Trophic structure and biomass distribution on two. East Cape rocky shores. A Mclachlan, H.W. Lombard and S. Louwrens. Zoology Department, University of Port Elizabeth, Port Elizabeth. The distribution and biomass of macrofauna and macroalgae is described for two intertidal rocky shores near Port Eliza ...

  9. Tuberculosis drug resistance in the Western Cape | Weyer | South ...

    African Journals Online (AJOL)

    Objectives: Drug resistance is a serious problem in the treatment of tuberculosis and a threat to successful tuberculosis control programmes. Local health workers have expressed concern that the increasing tuberculosis epidemic in the Western Cape is partly attributable to drug resistance. The aim of this study was to ...

  10. Autotomy, tail regeneration and jumping ability in Cape dwarf ...

    African Journals Online (AJOL)

    We examined jumping by the Cape dwarf gecko (Lygodactylus capensis) in terms of individuals' varying states of tail autotomy and regeneration. Although longer jumps were less likely to be successful (i.e. the animal would not successfully grip the surface and fell to the ground), there was no difference in the distance over ...

  11. Historical perspectives of mental health in the Eastern Cape

    African Journals Online (AJOL)

    The development of mental health services in the Eastern Cape Province is inextricably entwined in South Africa's colonial history and the racist policy of apartheid. Prior to the development of mental hospitals, mental health services were provided through a network of public and mission hospitals. This paper explores the ...

  12. COMMENTRY: Is climate change influence the decline of cape and ...

    African Journals Online (AJOL)

    COMMENTRY: Is climate change influence the decline of cape and bearded vultures in southern Africa. AR jenkins. Abstract. No Abstract. Vulture News Vol. 56 () 2007: pp.41-51. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online.

  13. Relative brain size in the mammalian carnivores of the Cape ...

    African Journals Online (AJOL)

    Relative brain sizes (encephalization quotients; EO) of the 30. Cape mammalian carnivores were calculated by regressing cranial volume against body mass. Within this taxon relative brain size appears to show no association with sociality, loco· motion, activity regimen or habitat, but is positively correlated with body mass.

  14. Involuntary admission of psychiatric patients in the Northern Cape ...

    African Journals Online (AJOL)

    mental healthcare user. The Northern Cape has five admin- istrative districts, comprising the Up- per Karoo, Frances Baard, Siyanda, the Namaqua region and Kgalagadi.3. The only mental healthcare facility avail- able in the province for involuntary ad- missions of psychiatric patients is the. West End Hospital in Kimberley.

  15. The Cape horse mackerel Trachurus trachurus capensis is an ...

    African Journals Online (AJOL)

    spamer

    The Cape horse mackerel Trachurus trachurus capensis is an important component of the Benguela ecosystem (Crawford et al. 1987). Two stocks are recognized, one in Namibian waters and the other ex- tending from south of the Orange River mouth to as far east as East London (Hecht 1990, Naish 1990,. Naish et al.

  16. Missed opportunities for immunisation at hospitals in the western Cape

    African Journals Online (AJOL)

    immunise children, and thereby improve vaccine coverage in the community, are missed. In February 1990, juSt before the national measles immunisation campaign, a study' was carried out at 8 hos- pitals in the western Cape to determine the extent of misse,d opportunities for measles immunisation in children.

  17. Foraging effort and prey choice in cape gannets | Adams | African ...

    African Journals Online (AJOL)

    In order to test the hypothesis that sardine Sardinops sagax are the preferred prey of Cape gannets Morus capensis, the link between foraging effort and prey choice was evaluated by simultaneously monitoring the activity and the diet of adult birds attending chicks at Bird Island, Algoa Bay, South Africa. Foraging trip ...

  18. Potable water use of residential consumers in the Cape Town ...

    African Journals Online (AJOL)

    The potable water use recorded by 3 579 residential consumer water meters in Cape Town, South Africa, was analysed as part of this research. The focus was on selected residential properties in serviced areas, with additional private access to groundwater as a supplementary household water source. Private consumers ...

  19. Prefabricated solution to modular construction in Cape Verde

    Science.gov (United States)

    Vieira, Nuno; Amado, Miguel; Pinho, Fernando

    2017-02-01

    Nowadays, the lack of adequate housing in Cape Verde is a growing problem. The migration of the population living in the countryside to the major cities generates an increase of the diameter of the cities. With the lack of economic power, the migrating families tend to occupy the land with houses which don't present proper conditions to living. Praia is the capital of Cape Verde and so on the biggest city of the country. This fact leads Praia to being the city with major economic power and job offer in all country. Consequently, Praia has developed the biggest slum of the Cape Verde and it is urgent to approach this problem in order to create solutions that reveal capacity to start solving it. Cape Verde's unique dry subtropical climate turns indispensable a careful resolution of the housing, in order to ensure the comfort of the occupants. The modular construction is a solution with potential to approach this problem with a fast and economic response. In order to answer the situation, this article introduces a modular solution in order to reach the needing of thermal comfort to the specific case of Praia.

  20. Distribution of blood lead levels in schoolchildren in selected cape ...

    African Journals Online (AJOL)

    Objective. To determine blood lead levels among children attending schools in selected Cape Peninsula suburbs, and to assess the impact of a reduction in the lead content of petrol. Design. A cross-sectional analytical study of children's blood lead levels and associated risk factors. Setting. Selected inner city, suburban, ...

  1. Haematology outreach clinics in the Free State and Northern Cape

    African Journals Online (AJOL)

    ary Health chnical nity. Guidelines alth nd 1996. e Services eport. Haematology outreach clinics in the Free State and Northern Cape. Marius J Coetzee, Philip N Badenhorst,. Engela P le ... Consultants from Bloemfontein held outpatient clinics in hospitals (with ... include academic stimulation of doctors and laboratories.

  2. Biodiversity status of urban remnant forests in Cape coast, Ghana ...

    African Journals Online (AJOL)

    Cape Coast Metropolis, which is close to Kakum forest, has its native forests being reduced to fragments. Biodiversity in these forest reserves are exposed to the threat of being cleared over night as a result of urbanization. There are reported cases of some rare or potential medicinal plant species that have disappeared ...

  3. Primary care morbidity in Eastern Cape Province | Brueton | South ...

    African Journals Online (AJOL)

    Primary care morbidity in Eastern Cape Province. V Brueton, P Yogeswaran, J Chandia, K Mfenyana, B Modell, M Modell, I Nazareth. Abstract. Background. Primary health care in rural South Africa is predominantly provided by remote clinics and health centres. In 1994, health centres were upgraded and new health centres ...

  4. Perinatal mortality in the Cape Province, 1989 - 1991

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... Objective. To determine the number of deliveries, the low- birth-weight rate and the perinatal mortality rate at provincial and province-aided hospitals and clinics in each planning region of the Cape Province. Design. A record of the number of deliveries, low-birth- weight infants, stillbirths and early neonataJ ...

  5. Underrecognition and undertreatment of asthma in Cape Town ...

    African Journals Online (AJOL)

    Background. In view of the high local prevalence of asthma, the extent of recognition and appropriate managementof childhood asthma was studied in a large suburban area of Cape Town. Design. Cross-sectional study based on random community sample of schools. Method. 1955 parents of sub B pupils from 16 schools ...

  6. Cape Town's central city development: A strategy of partnership and ...

    African Journals Online (AJOL)

    approach to urban planning through its. Development Guidelines for Land Use. Management (DGLUM) policy. In the final phase of development, this new way of analysing urban planning was developed in partnership with the City of Cape Town to promote a stronger dialogue between. City officials and the private sector.

  7. Human papillomavirus in normal cervical smears from Cape Town ...

    African Journals Online (AJOL)

    Objective: To determine the prevalence of human papillomavirus (HPV) types in South African women with normal cervical cytology and to determine whether our results are comparable to what has been found elsewhere in the wortd. Design: Cervical smears were collected from 262 women. Setting: The Cape Town ...

  8. Notification of pesticide poisoning in the western Cape, 1987 - 1991 ...

    African Journals Online (AJOL)

    There is a paucity of data on pesticide-related morbidity and mortality in South Africa. A review of notifications to the western Cape office of the Department of National Health and Population Development from 1987 to 1991 was undertaken to describe the epidemiological profile of pesticide poisoning in the region.

  9. Parotidectomy in Cape Town - a review of pathology and management

    African Journals Online (AJOL)

    Methods. A review of all parotidectomies performed by a single surgeon over a period of 10 years (1994 - 2004) in Cape Town, South Africa, is presented. Data were collected from a retrospective chart review. Results. One hundred and ninety-nine parotidectomies were performed and 196 pathology reports were reviewed.

  10. Aspects of the digestion in the Cape porcupine

    African Journals Online (AJOL)

    The digestive capabilities of the Cape porcupine (Hystrix africaeaustralis) ... On a high fibre diet food intake declined and retention time of digesta in the .... over 21 days, NDF = Neutral detergent fibre, CP = Crude protein, NS = not significant; * = different at P

  11. Afrikaans as an index of identity among Western Cape Coloured ...

    African Journals Online (AJOL)

    In South Africa, reports on language shift have focused on instances of language shift from indigenous African languages to English. There is, however, also research that suggests that language shift is taking place from Afrikaans to English in the Western Cape. Anthonissen (2009), for example, notes in her research ...

  12. Lexical borrowing by Khoekhoegowab from Cape Dutch and Afrikaans

    African Journals Online (AJOL)

    The present article instantiates types of lexical borrowing from Afrikaans and Dutch in Namibian Khoekhoegowab (also known as “Nama”/“Damara”), but occasionally also refers to borrowings in the opposite direction. Where evidence allows, loans are traced back beyond Afrikaans to the era of Cape Dutch and ...

  13. Health-promoting compounds in cape gooseberry (Physalis peruviana L.)

    NARCIS (Netherlands)

    Olivares-Tenorio, Mary Luz; Dekker, Matthijs; Verkerk, Ruud; Boekel, van Tiny

    2016-01-01

    Background The fruit of Physalis peruviana L., known as Cape Gooseberry (CG) is a source of a variety of compounds with potential health benefits. Therefore, CG has been subject of scientific and commercial interest. Scope and approach This review paper evaluates changes of such health-promoting

  14. Cape hake Merluccius capensis are abundant over the Namibian ...

    African Journals Online (AJOL)

    spamer

    Cape hake Merluccius capensis are abundant over the Namibian shelf. The population is typically segregated by size and their distributions are strongly related to depth (Botha 1985, Macpherson and Duarte. 1991, Reiss 1997). Hake recruits (15–25 cm) gener- ally inhabit the inner and midshelf, whereas medium-.

  15. Stock-environment recruitment analysis for Namibian Cape hake ...

    African Journals Online (AJOL)

    The factors modulating recruitment success of Cape hake Merluccius capensis in Namibian waters are still unresolved. In this study, we used generalised additive models, regression tree analysis and the conventional Ricker model to examine the effect of environmental indices and spawning stock biomass (SSB) on hake ...

  16. Growth of preschool coloured children in Cape Town | Molteno ...

    African Journals Online (AJOL)

    The growth of a random sample of coloured children in Cape Town was studied from birth until 5 years. At birth they were relatively light and short for gestational age. Size at birth correlated with social class. A rapid postnatal weight gain rendered them relatively overweight between 3 and 6 months. Thereafter they became ...

  17. A new adder ( Bitis ; Viperidae) from the Western Cape Province ...

    African Journals Online (AJOL)

    A new species of small, terrestrial Bitis is described from the Western Cape Province, South Africa. It occurs in sympatry with Bitis comuta and Bifis atropos on the upper slopes and summit of the Cedarberg, and with the latter on the Swartberg. Features of scalation, colour and body form distinguish the new species from all ...

  18. Bilingualism and language shift in Western Cape communities ...

    African Journals Online (AJOL)

    This paper considers a number of pertinent sociolinguistic aspects of a distinct process of language shift recently noted in some historically Afrikaans first language (L1) communities established in the Cape Metropolitan area. Particularly, it considers qualitatively how a number of families made deliberate choices to change ...

  19. Carbon and nitrogen losses through moulting in the Cape rock ...

    African Journals Online (AJOL)

    1987-11-28

    Nov 28, 1987 ... Afr. J. Zoo\\. 1988,23(3). 173. Carbon and nitrogen losses through moulting in the Cape rock lobster Jasus lalandii ... However, the annual cost of moulting to J. lalandii in terms of exuvial mass, which includes carbon and nitrogen, is ... the profound effect that light has on the moulting cycle. Similarly, Nelson ...

  20. Anthropometric profile of the coloured population of the Cape ...

    African Journals Online (AJOL)

    There were too few obese men to analyse in this manner. Many of the obese participants did not see themselves as obese. Only 19,7% of men and 45,2% of women had attempted to lose weight during the year preceding the study, in many cases using methods known to be ineffective. The coloureds of the Cape Peninsula ...

  1. Patterns and drivers of marine bioinvasions in eight Western Cape ...

    African Journals Online (AJOL)

    In South Africa, fouling is the dominant vector of marine invasions, being responsible for 48% of the 86 alien introductions that are known. This study aimed to document alien species in fouling assemblages in eight Western Cape harbours and to assess patterns and potential drivers of these invasions. In each harbour, 10 ...

  2. Reproduction in the Cape horseshoe bat (Rhinolophus capensis ...

    African Journals Online (AJOL)

    spermatogenesis and follicular development are. described and are· similar to those described for other members of the genus Rhinolophus. The reproductive cycle of the Cape horseshoe bat is characterized by spermatogenesis between. October and May (spring to autumn) with sperm released to the cauda epididymis in ...

  3. Temporality and Patterns of ART Adherence in the Western Cape

    African Journals Online (AJOL)

    In an ethnographic study conducted over thirty months in South Africa's Western Cape. Province ending in 2012, we explored ART adherence amongst almost 200 patients attending three clinics. This setting contained significant political, structural, economic and socio-cultural barriers to the uptake of, and adherence to, ...

  4. Interaction between Cape hake spawning and the circulation in the ...

    African Journals Online (AJOL)

    Cape hake in Namibian waters are demersal and mesopelagic spawners, spawning peaking offshore between 100 and 400 m deep, depending on local environmental conditions. The cross-shelf circulation, low-oxygen layers and mesoscale gyres are three important environmental factors influencing hake spawning ...

  5. Methamphetamine use and sexual risk behaviour in Cape Town ...

    African Journals Online (AJOL)

    In South Africa, it is. Methamphetamine use and sexual risk behaviour in Cape Town, South Africa: A review of data from 8 studies conducted between 2004 and 2007. CDH Parry1,2, A Plüddemann1, B Myers1, WM Wechsberg3, AJ Flisher4. 1Alcohol & Drug Abuse Research Unit, Medical Research Council, South Africa.

  6. Cape Mendocino, CA Earthquakes, April 25 & 26, 1992

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On April 25, 1992, a magnitude 7.1 earthquake occurred in the Cape Mendocino area. Two additional earthquakes, magnitudes 6.6 and 6.7 occurred the next morning. The...

  7. Archive of bathymetry data collected at Cape Canaveral, Florida, 2014

    Science.gov (United States)

    Hansen, Mark E.; Plant, Nathaniel G.; Thompson, David M.; Troche, Rodolfo J.; Kranenburg, Christine J.; Klipp, Emily S.

    2015-10-07

    Remotely sensed, geographically referenced elevation measurements of the sea floor, acquired by boat- and aircraft-based survey systems, were produced by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida, for the area at Cape Canaveral.

  8. Ekman estimates of upwelling at cape columbine based on ...

    African Journals Online (AJOL)

    Cape Columbine is a prominent headland on the south-west coast of Africa at approximately 32°50´S, where there is a substantial upwelling tongue, enhancing the ambient upwelling on the shelf, produced by wind-stress curl. From hourly records of wind measured there, the longshore component of wind stress was ...

  9. Depleted swell root beneath the Cape Verde Islands

    Science.gov (United States)

    Lodge, Alexandra; Helffrich, George

    2006-06-01

    The hotspot swell—an area of uplifted bathymetry or topography surrounding regional volcanism—is a defining hotspot characteristic, yet its origin is poorly understood. To test current ideas about swell formation, we studied the crust and shallow mantle structure of the Cape Verdes in a passive seismic experiment. The Cape Verde Islands are ˜450 km west of Senegal in the tropical Atlantic Ocean and are on the southwest flank of the Cape Verde Rise, the largest bathymetric anomaly in the oceans, rising ˜2 km above the surrounding seafloor (Crough, 1982). The archipelago occupies a unique position, an approximately stationary one in the hotspot frame of reference (Gripp and Gordon, 2002) and therefore with respect to the melting source believed to have produced it. Here we present an analysis of compressional to shear (P to S) converted seismic phases, recorded on a temporary network of seismograph stations on the Cape Verde Islands, that indicate a crust thickened to 22 km is underlain by a high-velocity, low-density layer, which overlies a zone of low shear-wave velocity starting at ˜80 km depth. We also measured shear-wave splitting delay times for teleseismic SKS phases, which are ˜0.81 s, compatible with an origin in this same layer. We interpret these observations as effects of hotspot melting, which produces a thickened crust and a depleted swell root that buoys the ocean floor and spreads laterally as it grows over time.

  10. Migrations of humpback whales past Cape Vidal, South Africa, and ...

    African Journals Online (AJOL)

    Shore-based surveys of migrating humpback whales Megaptera novaeangliae were undertaken from Cape Vidal, northern KwaZulu-Natal, South Africa, each year between 1988 and 1991, and in 2002. Daily observations of migrating whale groups were carried out from an approx. 60 m-high platform during all surveys.

  11. 15Th South African Psychology Congress, Cape Town, South Africa

    African Journals Online (AJOL)

    Test

    The 15th South African Psychology Congress of the Psychological Society of South. Africa (PsySSA) was hosted at the International Convention Centre in Cape Town (CTICC),. South Africa. The congress, under the theme Psychology: Past, Present and Future, took place from 11 to 14 August 2009. The first day was taken ...

  12. The filtering capacity of selected Eastern Cape estuaries, South Africa

    African Journals Online (AJOL)

    Four Eastern Cape estuaries, the Kromme, Gamtoos, Swartkops and Sundays Estuaries have a permanent connection to the adjacent ocean, but differ in the amount of freshwater inflows as well as in the land-use patterns in their respective catchment areas. The nutrient loading to the four estuaries in terms of phosphate, ...

  13. The diets of littoral fish from the Cape Peninsula

    African Journals Online (AJOL)

    Intertidal fish communities in the south·western Cape have a high density and biomass, implying that the fish are important con· sumers in the intertidal zone. Stomach content analyses of 20 species were undertaken to ascertain which food resources are most heavily exploited and the extent to which the co-existing.

  14. comparison of Cape Town and Durban business perceptions of the ...

    African Journals Online (AJOL)

    Local business concerns and perceptions are generally neglected in relation to mega event research. This article focuses on local business sector's perceptions of the 2010 FIFA World Cup in both Cape Town and Durban, and explores their experiences and impacts in terms of how the business sector was affected and ...

  15. Valuing water gains in the Eastern Cape's Working for Water ...

    African Journals Online (AJOL)

    drinie

    2002-01-01

    Jan 1, 2002 ... Valuing water gains in the Eastern Cape's Working for Water. Programme. SG Hosking* and M du Preez. Department of Economics and Economic History, University of Port Elizabeth, PO Box 1600, Port Elizabeth 6000, South Africa. Abstract. Water is one of the most important measured benefits of the ...

  16. (Bitis; Viperidae) from the Western Cape Province, South Africa

    African Journals Online (AJOL)

    1997-02-25

    Feb 25, 1997 ... Leiden 43(9): 107-115. SPAWLS, S. & BRANCH, W.R. 1995. Dangerous snakes of. Africa, Southern Books Pub!.. Johannesburg, 192p. VISSER, 1. 1979. New and reconfirmed records for the Cape. Province with notes on some 'rare' species (Sauria, Serpentes and. Anura). J Herpetol. Assoc. Afr. 21: 40-50.

  17. Who is the nutrition workforce in the Western Cape? | Goeiman ...

    African Journals Online (AJOL)

    Department of Health in the Western Cape, and establish whether it is adequate to meet the objectives of the INP. Method: Self-administered questionnaires compiled in English were used as the main data collection instrument for nutrition staff in districts and at hospitals (n = 647). Eight individual questionnaires, one per ...

  18. A Posteriori Integration of University CAPE Software Developments

    DEFF Research Database (Denmark)

    Tolksdorf, Gregor; Fillinger, Sandra; Wozny, Guenter

    2015-01-01

    This contribution deals with the mutual integration of existing CAPE software products developed at different universities in Germany, Denmark, and Italy. After the motivation MOSAIC is presented as the bridge building the connection between the modelling tool ICAS-MoT and the numerical processin...

  19. The English of White Eastern Cape Farmers in South Africa.

    Science.gov (United States)

    Gough, David

    1996-01-01

    Examines a particular "style of speech" used by a farming community in Eastern Cape Province, South Africa, which is characterized by code-switching with Xhosa and by prevalent terms of address. The social significance of the speech style in terms of the identity communicated is explored and discourse features are discussed. (Author/JL)

  20. Knowledge and attitudes in the rural Western Cape towards ...

    African Journals Online (AJOL)

    There is a need for pesticide water monitoring in South Africa and for community awareness with regard to chemical contamination of rural water sources. The results of two descriptive studies in the rural Western Cape are reported. One assessed water usage and the knowledge, attitudes and practices in relation to water of ...