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Sample records for alkaline pluton kola

  1. Pyroxenes of the Khibiny alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Yakovenchuk, V. N.; Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Men'shikov, Yu. P.; Konopleva, N. G.; Korchak, Yu. A.

    2008-12-01

    Seven pyroxene varieties were identified in nepheline syenites and foidolites of the Khibiny pluton: enstatite, ferrosilite, diopside, hedenbergite, augite, aegirine-augite, and aegirine. Enstatite and augite are typical of alkaline and ultramafic rocks of dike series. Ferrosilite was found in country quartzitic hornfels. Diopside is a rock-forming mineral in alkaline and ultramafic rocks, alkali gabbroids, hornfels in xenoliths of volcanic and sedimentary rocks and foyaite, melteigite-urtite that assimilate them, and certain hydrothermal pegmatite veins. Hedenbergite was noted in hornfels from xenoliths of volcanic and sedimentary rocks and in a hydrothermal pegmatite vein at Mount Eveslogchorr. Aegirine-augite is the predominant pyroxene in all types of nepheline syenites, phonolites and tinguaites, foidolites, alkaline and ultramafic rocks of dike series, fenitized wall rocks surrounding the pluton, and xenoliths of Devonian volcanic and sedimentary rocks. Aegirine is an abundant primary or, more often, secondary mineral in nepheline syenites, foidolites, and hydrothermal pegmatite veins. It occurs as separate crystals, outer zones of diopside and aegirine-augite crystals, and homoaxial pseudomorphs after Na-Ca amphiboles. Microprobe analyses of 265 pyroxenes samples allowed us to distinguish ten principal trends of isomorphic replacement and corresponding typomorphic features of pyroxenes. Compositional variations in clinopyroxenes along the sampled 35-km profile from the margin of the Khibiny pluton to its center confirm the symmetric zoning of the foyaite pluton relative to semicircular faults of the Minor Arc and the Main (Central) Ring marked by Devonian volcanic and sedimentary rocks, foidolites, and related metasomatic rocks (rischorrite, albitite, and aegirinite). Changes in the composition of pyroxenes are explained mainly by the redistribution of elements between coexisting minerals of foyaites in the process of their intense differentiation under the

  2. Amphiboles of the Khibiny alkaline pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Konopleva, N. G.; Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Men'shikov, Yu. P.; Korchak, Yu. A.

    2008-12-01

    The rocks of the Khibiny pluton contain 25 amphibole varieties, including edenite, fluoredenite, kaersutite, pargasite, ferropargasite, hastingsite, magnesiohastingsite, katophorite, ferrikatophorite, magnesiokatophorite, magnesioferrikatophorite, magnesioferrifluorkatophorite, ferrimagnesiotaramite, ferrorichterite, potassium ferrorichterite, richterite, potassium richterite, potassium fluorrichterite, arfvedsonite, potassium arfvedsonite, magnesioarfvedsonite, magnesioriebeckite, ferriferronyboite, ferrinyboite, and ferroeckermannite. The composition of rock-forming amphiboles changes symmetrically relative to the Central Ring of the pluton; i.e., amphiboles enriched in K, Ca, Mg, and Si are typical of foyaite near and within the Central Ring. The Fe and Mn contents in amphiboles increase in the direction from marginal part of the pluton to its center. Foyaite of the marginal zone contains ferroeckermannite, richterite, arfvedsonite, and ferrorichterite; edenite is typical of foyaite and hornfels of the Minor Arc. Between the Minor Arc and the Central Ring, foyaite contains ferroeckermannite, arfvedsonite, and richterite; amphiboles in rischorrite, foidolite and hornfels of the Central Ring are (potassium) arfvedsonite, (potassium) richterite, magnesiokatophorite, magnesioarfvedsonite, ferroeckermannite, and ferriferronyboite; amphiboles in foyaite within the Central Ring, in the central part of the pluton, are arfvedsonite, magnesioarfvedsonite, ferriferronyboite, katophorite, and richterite. It is suggested that such zoning formed due to the alteration of foyaite by a foidolite melt intruded into the Main (Central) Ring Fault.

  3. Typomorphism of fluorapatite in the Khibiny alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Konopleva, N. G.; Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Mikhailova, Yu. A.

    2014-12-01

    The zoning of accessory and rock-forming fluorapatite in the Khibiny pluton is discussed in its content, morphology, and chemical composition. The concentrations of Na, REE, and Si impurities in fluorapatite decrease from the margin and center of the pluton to the Major Ring, composed of melteigiteurtite and rischorrite. Within this structure, the purest apatite is characteristic of the high-grade ore in large deposits, where it occurs free of Na, and REE, as well as Sr in place of Ca. The fractal dimension of fluorapatite aggregates in all textural types of apatite-nepheline rocks (ores) corresponds to the dimension of fractures. Along with mineralogy of apatite-nepheline rocks and zoning of host foidolite, this feature indicates the superimposed character of apatite mineralization.

  4. Corundum-group minerals in rocks of the Khibiny alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Mikhailova, Yu. A.; Konopleva, N. G.; Yakovenchuk, V. N.; Ivanyuk, G. Yu.; Men'shikov, Yu. P.; Pakhomovsky, Ya. A.

    2007-12-01

    Five minerals of the corundum group have been identified in the Khibiny pluton with certainty. Corundum proper and karelianite occur only in hornfels after volcanic and sedimentary rocks. Xenoliths of hornfels mark the ring faults that bound foidalite within the field of foyaite. Hematite occurs in hydrothermally altered nepheline syenite and crosscutting hydrothermal veins related to the ring faults. Minerals of the ilmenite-pyrophanite series are present in all rocks of the pluton, including veins. Accessory ilmenite in foyaite varies from the manganese variety and pyrophanite in the inner and outer parts of the pluton to manganese-free ilmenite in zone of the Main Ring Fault. In xenoliths of volcanic rocks and alkaline ultramafic rocks, ilmenite is enriched in magnesium. The zoning in distribution of the above-mentioned minerals and the character of variation in their compositions from margins of the pluton to its center are consistent with the petrochemical zoning formed as a result of foyaite alteration of near ring faults.

  5. Spinel-group minerals in rocks of the Khibiny alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Konopleva, N. G.; Yakovenchuk, V. N.; Men'shikov, Yu. P.; Mikhailova, Yu. A.

    2007-12-01

    Seven spinel-group minerals in various geological settings have been revealed in the rocks of the Khibiny pluton. Hercynite, gahnite, and vuorelainenite occur only in xenoliths of hornfels after volcanic and sedimentary rocks, whereas spinel and magnesiochromite occur in alkaline ultramafic rocks of dike series. Franklinite has been discovered in a low-temperature hydrothermal vein. Ubiquitous magnetite is abundant in foyaite, foidolites, alkaline ultrabasic rocks, and pegmatite and hydrothermal veins and may even be the main mineral in some foidolite varieties. The spinel-group minerals are characterized by various chemical compositions due to the fractionation of nepheline syenites resulting in formation of the Main ring of foidolites and apatite-nepheline ore. Like most other minerals found throughout the pluton, magnetite is characterized by variation in the chemical composition along the radial line from the contact with country Proterozoic volcanic rocks to the geometric center of the pluton. Toward the center, the total Ti and Mn contents in magnetite increase from 5 15 up to 40 at %.

  6. Typochemistry of rinkite and products of its alteration in the Khibiny Alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Konopleva, N. G.; Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Mikhailova, Yu. A.; Selivanova, E. A.

    2015-12-01

    The occurrence, morphology, and composition of rinkite are considered against the background of zoning in the Khibiny pluton. Accessory rinkite is mostly characteristic of foyaite in the outer part of pluton, occurs somewhat less frequently in foyaite and rischorrite in the central part of pluton, even more sparsely in foidolites and apatite-nepheline rocks, and sporadically in fenitized xenoliths of the Lovozero Formation. The largest, up to economic, accumulations of rinkite are related to the pegmatite and hydrothermal veins, which occur in nepheline syenite on both sides of the Main foidolite ring. The composition of rinkite varies throughout the pluton. The Ca, Na, and F contents in accessory rinkite and amorphous products of its alteration progressively increase from foyaite and fenitized basalt of the Lovozero Formation to foidolite, rischorrite, apatite-nepheline rocks, and pegmatite-hydrothermal veins.

  7. Rock-Forming feldspars of the Khibiny alkaline pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Konopleva, N. G.; Kalashnikov, A. O.; Korchak, Yu. A.; Selivanova, E. A.; Yakovenchuk, V. N.

    2010-12-01

    This paper describes the structural-compositional zoning of the well-known Khibiny pluton in regard to rock-forming feldspars. The content of K-Na-feldspars increases inward and outward from the Main foidolite ring. The degree of coorientation of tabular K-Na-feldspar crystals sharply increases in the Main ring zone, and microcline-dominant foyaite turns into orthoclase-dominant foyaite. The composition of K-Na-feldspars in the center of the pluton and the Main ring zone is characterized by an enrichment in Al. This shift is compensated by a substitution of some K and Na with Ba (the Main ring zone) or by an addition of K and Na cations to the initially cation-deficient microcline (the central part of the pluton). Feldspars of volcanosedimentary rocks occurring as xenoliths in foyaite primarily corresponded to plagioclase An15-40, but high-temperature fenitization and formation of hornfels in the Main ring zone gave rise to the crystallization of anorthoclase subsequently transformed into orthoclase and albite due to cooling and further fenitization. Such a zoning is the result of filling the Main ring fault zone within the homogeneous foyaite pluton with a foidolite melt, which provided the heating and potassium metasomatism of foyaite and xenoliths of volcanosedimentary rocks therein. The process eventually led to the transformation of foyaite into rischorrite-lyavochorrite, while xenoliths were transformed into aluminum hornfels with anorthoclase, annite, andalusite, topaz, and sekaninaite.

  8. Kyanoxalite, a new cancrinite-group mineral species with extraframework oxalate anion from the Lovozero alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Chukanov, N. V.; Pekov, I. V.; Olysych, L. V.; Massa, W.; Yakubovich, O. V.; Zadov, A. E.; Rastsvetaeva, R. K.; Vigasina, M. F.

    2010-12-01

    Kyanoxalite, a new member of the cancrinite group, has been identified in hydrothermally altered hyperalkaline rocks and pegmatites of the Lovozero alkaline pluton, Kola Peninsula, Russia. It was found at Mount Karnasurt (holotype) in association with nepheline, aegirine, sodalite, nosean, albite, lomonosovite, murmanite, fluorapatite, loparite, and natrolite and at Mt. Alluaiv. Kyanoxalite is transparent, ranging in color from bright light blue, greenish light blue and grayish light blue to colorless. The new mineral is brittle, with a perfect cleavage parallel to (100). Mohs hardness is 5-5.5. The measured and calculated densitiesare 2.30(1) and 2.327 g/cm3, respectively. Kyanoxalite is uniaxial, negative, ω = 1.794(1), ɛ = 1.491(1). It is pleochroic from colorless along E to light blue along O. The IR spectrum indicates the presence of oxalate anions C2O{4/2-} and water molecules in the absence of CO{3/2-} Oxalate ions are confirmed by anion chromatography. The chemical composition (electron microprobe; water was determined by a modified Penfield method and carbon was determined by selective sorption from annealing products) is as follows, wt %: 19.70 Na2O, 1.92 K2O, 0.17 CaO, 27.41 Al2O3, 38.68 SiO2, 0.64 P2O5, 1.05 SO3, 3.23 C2O3, 8.42 H2O; the total is 101.18. The empirical formula (Z = 1) is (Na6.45K0.41Ca0.03)Σ6.89(Si6.53Al5.46O24)[(C2O4)0.455(SO4)0.13(PO4)0.09(OH)0.01]Σ0.68 · 4.74H2O. The idealized formula is Na7(Al5-6Si6-7O24)(C2O4)0.5-1 · 5H2O. Kyanoxalite is hexagonal, the space group is P63, a = 12.744(8), c = 5.213(6) -ray powder diffraction pattern are as follows, [ d, [A] ( I, %)( hkl)]: 6.39(44) (110), 4.73 (92) (101), 3.679 (72) (300), 3.264 (100) (211, 121), 2.760 (29) (400), 2.618 (36) (002), 2.216, (29) (302, 330). According to the X-ray single crystal study ( R = 0.033), two independent C2O4 groups statistically occupy the sites on the axis 63. The new mineral is the first natural silicate with an additional organic anion and is the most

  9. Relationship between oxosilicate niobium mineralization and organic matter in alkaline pegmatites of the Khibiny pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Chukanov, N. V.; Pekov, I. V.; Perepelitsina, E. O.; Ermolaeva, V. N.; Vozchikova, S. A.

    2010-12-01

    In alkaline pegmatites of the Khibiny pluton niobium oxosilicates with (Nb + Ti)/Si ≥ 1 and Nb > Ti occur in intimate fine intergrowths with endogenic organic matter, which makes it possible to assume a genetic relationship between them. Such intergrowths from pegmatites of Mounts Kukisvumchorr and Koashva have been studied by electron microscopy, electron microprobe, IR spectroscopy, and exclusion chromatography. Unsaturated hydrocarbon groups, including aromatic ones, and carboxylate groups are prevalent in the organic matter intergrown with the niobium oxosilicates. The molecular weight distribution in the part of the bitumen soluble in tetrahydrofurane is polymodal, probably due to its formation as a result of parallel reactions on several catalytic centers of polymerization.

  10. Yegorovite, Na4[Si4O8(OH)4]·7H2O, a new mineral from the Lovozero alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Zubkova, N. V.; Chukanov, N. V.; Zadov, A. E.; Grishin, V. G.; Pushcharovsky, D. Yu.

    2010-12-01

    A new mineral, yegorovite, has been identified in the late hydrothermal, low-temperature assemblage of the Palitra hyperalkaline pegmatite at Mt. Kedykverpakhk, Lovozero alkaline pluton, Kola Peninsula, Russia. The mineral is intimately associated with revdite and megacyclite, earlier natrosilite, microcline, and villiaumite. Yegorovite occurs as coarse, usually split prismatic (up to 0.05 × 0.15 × 1 mm) or lamellar (up to 0.05 × 0.7 × 0.8 mm) crystals. Polysynthetic twins and parallel intergrowths are typical. Mineral individuals are combined in bunches or chaotic groups (up to 2 mm); radial-lamellar clusters are less frequent. Yegorovite is colorless, transparent with vitreous luster. Cleavage is perfect parallel to (010) and (001). Fracture is splintery; crystals are readily split into acicular fragments. The Mohs hardness is ˜2. Density is 1.90(2) g/cm3 (meas) and 1.92 g/cm3 (calc). Yegorovite is biaxial (-), with α = 1.474(2), β = 1.479(2), and γ = 1.482(2), 2 V meas > 70°, 2 V calc = 75°. The optical orientation is X ∧ a ˜ 15°, Y = c, Z = b. The IR spectrum is given. The chemical composition determined using an electron microprobe (H2O determined from total deficiency) is (wt %): 23.28 Na2O, 45.45 SiO2, 31.27 H2Ocalc; the total is 100.00. The empirical formula is Na3.98Si4.01O8.02(OH)3.98 · 7.205H2O. The idealized formula is Na4[Si4O8(OH)4] · 7H2O. Yegorovite is monoclinic, space group P21/ c. The unit-cell dimensions are a = 9.874, b= 12.398, c = 14.897 Å, β = 104.68°, V = 1764.3 Å3, Z = 4. The strongest reflections in the X-ray powder pattern ( d, Å ( I, %)([ hkl]) are 7.21(70)[002], 6.21(72)[012, 020], 4.696(44)[022], 4.003(49)[211], 3.734(46)[ bar 2 13], 3.116(100)[024, 040], 2.463(38)[ bar 4 02, bar 2 43]. The crystal structure was studied by single-crystal method, R hkl = 0.0745. Yegorovite is a representative of a new structural type. Its structure consists of single chains of Si tetrahedrons [Si4O8(OH)4]∞ and sixfold polyhedrons

  11. Structural paragenesis as an indicator of the origin of alkaline rocks in the ijolite-urtite arc of the Khibiny pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Kulakovsky, A. L.

    2015-03-01

    The results of structural analysis of the ore-bearing complex in the Khibiny pluton are presented. A multistage history of the formation of the ijolite-urtite arc structure has been established. The conic shear zone that determines the structural appearance of the ore-bearing complex is related to the early deformation stage. Only massive ijolite and melteigite are rocks of predeformation matrix. All other rock varieties and apatite ore are syndeformation (gneissic ijolite) or postdeformation (urtite, apatite ore) and thus are not magmatic in origin. The formation of the Paleozoic conic shear zone was most likely predetermined by a Precambrian central-type structure, more precisely, by a binucleus vortex structure related to shearing.

  12. Fluorcanasite, K3Na3Ca5Si12O30(F,OH)4 · H2O, a new mineral species from the Khibiny alkaline pluton, Kola Peninsula, Russia, and new data on canasite

    NASA Astrophysics Data System (ADS)

    Khomyakov, A. P.; Nechelyustov, G. N.; Krivokoneva, G. K.; Rastsvetaeva, R. K.; Rozenberg, K. A.; Rozhdestvenskaya, I. V.

    2009-12-01

    Fluorcanasite is described, a new mineral species found in dumps of the Kirovsk apatite mine, Mt. Kukisvumchorr, Khibiny alkaline pluton, Kola Peninsula, Russia. The new mineral is associated with microcline, nepheline, aegirine, scherbakovite, lamprophyllite, pectolite, mosandrite, villiaumite, rasvumite, and molybdenite. It occurs as prismatic crystals up to 0.2-0.3 × 1-2 mm in size extending along [010]. Fluorcanasite is purple, transparent, with white streak and vitreous luster. The fracture is hackly along the extension and stepped in other directions. The mineral is brittle. The cleavage is eminent parallel to {100} and {201} and perfect parallel to {001}. D(meas) = 2.68(2) g/cm3 (volumetric method); D(calc) = 2.69 g/cm3. Fluorcanasite is biaxial, negative, n α = 1.538(1), n β = 1.546(1), n γ = 1.549(1), 2 V(meas) = 60(2)°, 2 V(calc) = 63°. Dispersion r > v. The new mineral is pleochroic according to the scheme N β > N γ > N α; N β is purple, N γ is lilac, and N α is amber-yellow. Orientation is as follows: b = N β, a∧ N γ = 3°, c∧ N α = 19°. Fluorcanasite is not luminescent in UV light and slowly decomposes in acid. The new mineral is monoclinic, space group Cm, a = 18.846(4), b = 7.242(1), c = 12.650(2) Å, β = 111.84(2)°, V = 1602.6(4) Å3, Z = 2. The strongest reflections [ d, Å( I)] in the X-ray powder pattern of a grainoriented sample are 2.915(100), 4.204(40), 5.872(36), 4.712(36), 2.358(32), 3.012(24), 2.310(24), 3.082(24) and the same reflections in a randomly oriented sample are 3.082(100), 2.915(85), 4.712(46), 4.204(41), 3.340(35), 5.872(33), 2.658(30). The chemical composition, determined with an electron microprobe, is as follows, wt %: 7.19 Na2O, 10.91 K2O, 19.55 CaO, 0.27 FeO, 2.08 MnO, 55.84 SiO2, 4.10 F, 2.22 H2O (determined on the basis of structural data), 1.73-O = F2; the total is 100.43. The empirical formula, calculated on the basis of Si = 12, is K2.99Na3.00(Ca4.50Mn0.38·Fe{0.05/2+})Σ4.93Si12O29.93(F2.79OH1

  13. Shlykovite KCa[Si4O9(OH)] · 3H2O and cryptophyllite K2Ca[Si4O10] · 5H2O, new mineral species from the Khibiny alkaline pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Zubkova, N. V.; Filinchuk, Ya. E.; Chukanov, N. V.; Zadov, A. E.; Pushcharovsky, D. Yu.; Gobechiya, E. R.

    2010-12-01

    New minerals, shlykovite and cryptophyllite, hydrous Ca and K phyllosilicates, have been identified in hyperalkaline pegmatite at Mount Rasvumchorr, Khibiny alkaline pluton, Kola Peninsula, Russia. They are the products of low-temperature hydrothermal activity and are associated with aegirine, potassium feldspar, nepheline, lamprophyllite, eudialyte, lomonosovite, lovozerite, tisinalite, shcherbakovite, shafranovskite, ershovite, and megacyclite. Shlykovite occurs as lamellae up to 0.02 × 0.02 × 0.5 mm in size or fibers up to 0.5 mm in length usually combined in aggregates up to 3 mm in size, crusts, and parallel-columnar veinlets. Cryptophyllite occurs as lamellae up to 0.02 × 0.1 × 0.2 mm in size intergrown with shlykovite being oriented parallel to {001} or chaotically arranged. Separate crystals of the new minerals are transparent and colorless; the aggregates are beige, brownish, light cream, and pale yellowish-grayish. The cleavage is parallel to (001) perfect. The Mohs hardness of shlykovite is 2.5-3. The calculated densities of shlykovite and cryptophyllite are 2.444 and 2.185 g/cm3, respectively. Both minerals are biaxial; shlykovite: 2 V meas = -60(20)°; cryptophyllite: 2 V meas > 70°. The refractive indices are: shlykovite: α = 1.500(3), β = 1.509(2), γ = 1.515(2); cryptophyllite: α = 1.520(2), β = 1.523(2), γ = 1.527(2). The chemical composition of shlykovite determined by an electron microprobe (H2O determined from total deficiency) is as follows, wt %: 0.68 Na2O, 11.03 K2O, 13.70 CaO, 59.86 SiO2, 14.73 H2O; the total is 100.00. The empirical formula calculated on the basis of 13 O atoms (OH/H2O calculated from the charge balance) is (K0.96Na0.09)Σ1.05Ca1.00Si4.07O9.32(OH)0.68 · 3H2O. The idealized formula is KCa[Si4O9(OH)] · 3H2O. The chemical composition of cryptophyllite determined by an electron microprobe (H2O determined from the total deficiency) is as follows, wt %: 1.12 Na2O, 17.73 K2O, 11.59 CaO, 0.08 Al2O3, 50.24 SiO2, 19.24 H2

  14. Elpasolite from hyperalkaline pegmatite of the Khibiny pluton, Kola Peninsula. Symmetry of elpasolite

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Chukanov, N. V.; Kononkova, N. N.; Zubkova, N. V.; Rabadanov, M. Kh.; Pushcharovsky, D. Yu.

    2008-12-01

    Elpasolite, K2NaAlF6, has been found for the first time in a pegmatite related to peralkaline foid syenite at Mt. Koashva, Khibiny alkaline pluton, Kola Peninsula, Russia, as pale pink octahedral crystals up to 2 mm in size within cavities in the natrolite core of pegmatite in association with amicite, sodalite, aegirine, pectolite, catapleiite, sitinakite, lemmleinite-K, and vinogradovite. The chemical composition determined with an electron microprobe is as follows, wt %: 31.53 K; 9.22 Na; 11.20 Al; 47.21 F; total is 99.16. The empirical formula is K1.96Na0.98Al1.01F6.05. The infrared spectrum is given. The crystal structure has been refined to R = 0.030, space group Fm bar 3 m, a = 8.092 Å. The result of a special X-ray powder diffraction study confirmed the suggestion made by Morss (1974) that reflections violating space group Fm bar 3 m in some published X-ray powder patterns of natural elpasolite are Kβ-lines.

  15. Davinciite, Na12K3Ca6Fe{3/2+}Zr3(Si26O73OH)Cl2, a New K,Na-Ordered mineral of the eudialyte group from the Khibiny Alkaline Pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Khomyakov, A. P.; Nechelyustov, G. N.; Rastsvetaeva, R. K.; Rozenberg, K. A.

    2013-12-01

    This paper presents a description of a new zirconosilicate of the eudialyte group, which was named davinciite in honor of Leonardo da Vinci (1452-1519), a famous Italian scientist, painter, sculptor and architect. The new mineral has been found in hyperagpaitic pegmatite at the Rasvumchorr Mountain, Khibiny Pluton, Kola Peninsula, as relict inclusions, up to 1-2 mm in size in a rastsvetaevite matrix. It is associated with nepheline, sodalite, potassium feldspar, delhayelite, aegirine, shcherbakovite, villiaumite, nitrite, nacaphite, rasvumite, and djerfisherite. Davinciite is dark lavender and transparent, with a vitreous luster and white streak. The new mineral is brittle, with conchoidal fracture; the Mohs' hardness is 5. No indications of cleavage or parting were observed. The measured density is 2.82(2) g/cm3 (volumetric method); the calculated density is 2.848 g/cm3. Davinciite is optically uniaxial, positive; ω = 1.603(2), ɛ = 1.605(2). It is nonpleochroic and nonfluorescent in UV light. The new mineral slowly breaks down and gelates in 50% HCl and HNO3. It is trigonal, space group R3m. The unit-cell dimensions are a = 14.2956(2), c = 30.0228(5) Å, V=5313.6(2) Å3. The strongest reflections in the X-ray powder diffraction pattern [ d, Å ( I, %) ( hkl)] are as follows: 2.981(100)(315), 2.860(96)(404), 4.309(66)(205), 3.207(63)(208), 6.415(54)(104), 3.162(43)(217). The chemical composition (electron microprobe, H2O calculated from X-ray diffraction data) is as follows, wt %: 12.69 Na2O, 3.53 K2O, 11.02 CaO, 0.98 SrO, 0.15 BaO, 5.33 FeO, 0.37 MnO, 0.07 Al2O3, 51.20 SiO2, 0.39 TiO2, 11.33 ZrO2, 0.21HfO2, 0.09 Nb2O5, 1.89 Cl, 0.93H2O, -O = Cl2 0.43; total is 99.75. The empirical formula calculated on the basis of Si + Al + Zr + Hf + Ti + Nb = 29 ( Z = 3) is (Na1l.75Sr0.29Ba0.03)Σ12.07(K2.28Na0.72)Σ3Ca5.99(Fe2.26Mn0.16)Σ2.42(Zr2.80Ti0.15Hf0.03Nb0.02) Σ3(Si1.96Al0.04)Σ2[Si3O9]2 [Si9O27]2[(OH)1.42O0.58]Σ2[Cl1.62(H2O)0.38]Σ2 · 0.48H2O. The simplified

  16. Kalsilite of the Khibiny and Lovozero alkaline plutons, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Ivanyuk, G. Yu.

    2009-12-01

    Kalsilite—a typical mineral of ore-bearing zones of the Khibiny and Lovozero plutons—was formed after low-Si and high-K nepheline in one of three ways: (1) by relatively high-temperature replacement of Na with K; (2) due to orthoclase-kalsilite poikiloblastesis in foidolites and overlapping foyaites; or (3) by replacement of nepheline with zeolite.

  17. Voronkovite, Na15(Na,Ca,Ce)3(Mn,Ca)3Fe3Zr3Si26O72(OH,O)4Cl · H2O, a new mineral species of the eudialyte group from the Lovozero alkaline pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Khomyakov, A. P.; Nechelyustov, G. N.; Rastsvetaeva, R. K.

    2009-12-01

    This paper describes a new member of the eudialyte group named in honor of Alexander Alexandrovich Voronkov (1928-1982), the prominent Russian crystallographer. The new mineral has been found in the Shkatulka hyperalkaline pegmatite body at Mt. Alluaiv, Lovozero alkaline pluton, Kola Peninsula, Russia. The mineral is associated with microcline, sodalite, nepheline, aegirine, terskite, lomonosovite, vuonnemite, shkatulkalite, manganoneptunite, and sphalerite. Voronkovite occurs as rounded, poorly faced crystals up to 2-5 mm across. The new mineral is light brown, with vitreous luster and conchoidal fracture. The streak is white. Voronkovite is transparent and brittle; the Mohs hardness is 5; cleavage or parting is not observed. D(meas) = 2.97(2) g/cm3 (volumetric method); D(calc) = 2.95 g/cm3. The new mineral is uniaxial, positive, pleochroic from lemon yellow along X to brownish pink along Y, and is not luminescent in UV light. Voronkovite easily dissolves and gelates in acid at room temperature. The new mineral is trigonal, space group R3, a = 14.205(7), c = 30.265(15) Å, V = 5289(8) Å3, Z = 3. The strongest reflections in the X-ray diffraction pattern [ d, Å ( I)( hkl)] are 2.970(100)(315), 4.316(85)(205), 2.848(84)(404), 3.221(43)(208), 3.536(41)(027), 3.039(41)(119). The chemical composition (electron microprobe, H2O determined with chemical analysis) is as follows, wt %: 15.84 Na2O, 0.28 K2O, 3.08 CaO, 1.76 SrO, 4.65 MnO, 3.53 FeO, 0.93 La2O3, 1.36 Ce2O3, 0.68 Nd2O3, 0.15 Al2O3, 49.48 SiO2, 0.33 TiO2, 14.11 ZrO2, 0.23 HfO2, 0.91 Nb2O5, 0.44 Cl, 0.21 F, 1.56 H2O, 0.19 -O = (Cl,F)2; total is 99.34. The empirical formula calculated on the basis of Si + Al = 26 ( Z = 3) is as follows: (Na13.96Sr0.54K0.19)Σ14.69(Na1.64Ca0.92Ce0.26 La0.18)Σ3.00(Mn2.06Ca0.81Nd0.13)Σ3.00(F1.54Zr0.60Na0.48Nb0.21Ti0.13Hf0.04)Σ3.00Zr3.00(Si1.91Al0.09)Σ2.00(Si24O72)[(OH)2.98 O1.02]Σ4(Cl0.39F0.35)Σ0.74 · 1.23H2O. The simplified formula is Na15(Na,Ca,Ce)3(Mn,Ca)3Fe3Zr3Si26O72(OH

  18. Uranium-lead dating of perovskite from the Afrikanda plutonic complex (Kola Peninsula, Russia) using LA-ICP-MS.

    NASA Astrophysics Data System (ADS)

    Reguir, E.; Camacho, A.; Yang, P.; Chakhmouradian, A. R.; Halden, N. M.

    2009-04-01

    Perovskite (CaTiO3) is a common early crystallizing accessory phase in a variety of alkaline rocks, and has been shown to contain enough U and Th for U-Pb dating. U and Pb analysis of perovskite has been primarily carried out using the SHRIMP or ID-TIMS techniques, and the resulting U-Pb dates commonly yield the emplacement age of the host rock. To our knowledge, only one U-Pb study of perovskite has been done using the LA-ICP-MS (Cox and Wilton, 2006). Some of the advantages of this method over the SHRIMP and ID-TIMS techniques include greater speed and lower cost of analysis. In this work, the U-Pb ages of perovskite from the Afrikanda plutonic complex (Russia) were obtained in situ using the LA-ICP-MS. The measured 238U/206Pb and 207Pb/206Pb ratios were corrected for time-dependent mass-bias using the well-calibrated zircon standard GJ-1 (608.5 ± 0.4 Ma; Jackson et al., 2004). On a Tera-Wasserburg diagram (Tera and Wasserburg, 1972) the analyses of perovskite from two magmatic phases (clinopyroxenite and carbonatite) plot in separate clusters. Although the variations in the 238U/206Pb and 207Pb/206Pb ratios within each group are small, there is enough dispersion between the two clusters to obtain a reasonably precise age of 375 ± 13 Ma (2; MSWD = 0.23), which strongly suggests that the carbonatitic rocks are broadly coeval with the clinopyroxenite. The only other isotopic study on the Afrikanda Complex was done on a clinopyroxenite using the Rb-Sr method and yielded a whole rock-mineral (perovskite, biotite, augite and apatite) isochron age of 364.0 ± 3.1 Ma (2; MSWD = 0.72). This age is within error of our U-Pb date, which demonstrates that LA-ICP-MS-based U-Pb dating of perovskite can serve as a reliable geochronological tool. References Cox, R.A. and Wilton, D.H.C. (2006) U-Pb dating of perovskite by LA-ICP-MS: An example from the Oka carbonatite, Quebec, Canada. Chem. Geol., 235, 21-32. Jackson, S.E., Pearson, N.J., Griffin, W.L. and Belousova, E.A. (2004

  19. Andrianovite, Na12(K,Sr,Ce)3Ca6Mn3Zr3Nb(Si25O73)(O, H2O,OH)5, a new potassium-rich mineral species of the eudialyte group from the Khibiny alkaline Pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Khomyakov, A. P.; Nechelyustov, G. N.; Rastsvetaeva, R. K.; Rozenberg, K. A.

    2008-12-01

    This paper presents the description of a new eudialyte-group mineral, which was named andrianovite in honor of Valerii Ivanovich Andrianov (1938-1991), a famous Russian mathematician and crystallographer, who developed the AREN software package for structural study of minerals with variable composition. The new mineral has been found in pegmatite from the Koashva open pit, Khibiny Pluton, Kola Peninsula, as rims 0.1-1.0 mm wide surrounding the crystals of typical eudialyte. Aegirine, sodalite, microcline, natrolite, lomonosovite, lamprophyllite, mosandrite, and villiaumite are associated minerals. Andrianovite is light yellow, with vitreous luster and stepped fracture. It is transparent or turbid, with a white streak. The new mineral is brittle; the Mohs hardness is 5. The cleavage is imperfect parallel to (001). The measured density is 2.93(2) g/cm3 (volumetric method); the calculated density is 3.02 g/cm3. Andrianovite is optically uniaxial, negative; ω = 1.622(2), ɛ= 1.617(2). It is nonfluorescent and nonpleochroic. The new mineral slowly breaks down and gelates in 50% HCl and HNO3 at room temperature. It is trigonal, space group R3 m. The unit cell dimensions are a = 14.281(4), c = 30.243(7) Å, V = 5342(4) Å3. The strongest reflections in the X-ray powder pattern [ d, Å ( I, %)( hkl)] are as follows: 2.982(100)(315), 2.860(94)(404), 4.322(71)(205), 3.222(70)(208), 6.447(60)(104), 3.170(50)(217), 5.719(40)(202), 3.540(38)(027). The chemical composition (electron microprobe, H2O and CO2 determined by chemical analysis) is as follows, wt %: 11.61 Na2O, 2.05 K2O, 10.26 CaO, 3.11 SrO, 0.19 BaO, 3.97 MnO, 2.43 FeO, 0.81 La2O3, 1.73 Ce2O3, 0.52 Nd2O3, 0.28 Y2O3, 0.02 Al2O3, 47.06 SiO2, 0.12 TiO2, 11.32 ZrO2, 0.26 HfO2, 2.84 Nb2O5, 0.31 Cl, 0.57 CO2, 0.87 H2O, -O = 0.07 Cl2; total is 100.26. The empirical formula atcat = 53 ( Z= 3) is Na12.09(K1.40Sr0.97REE0.60Ba0.04)Σ3.01(Ca5.90Y0.08).98(Mn1.81)Fe{1.19/2+} Σ2.90(Zr2.96Hf0.04)Σ3.0(Nb0.69Si0.27Ti0.05Al0.01)Σ1

  20. Late Proterozoic and Silurian alkaline plutons within the southeastern New England Avalon zone

    SciTech Connect

    Hermes, O.D. ); Zartman, R.E. )

    1992-07-01

    Distinct pulses of quartz-bearing, alkaline plutonism and volcanism are known to have occurred in the Avalon zone of southeastern New England during the Late Ordovician, Early Silurian, Devonian, and Carboniferous. Zircon separates from the Franklin and Dartmouth plutons demonstrate that two additional, previously unrecognized periods of alkaline magmatism occurred. The Franklin pluton yields an age of 417 {plus minus} 6 Ma (Late Silurian), whereas the Dartmouth pluton is Late Proterozoic (595 {plus minus} 5 Ma) and markedly older than the other plutons of alkaline affinity. The new ages further emphasize the episodic nature and long-term duration of such alkaline igneous events within the southeastern New England Avalon zone. The Dartmouth pluton may represent a post-collisional alkaline granite emplaced in the Late Proterozoic, almost immediately after a major period of calcalkaline igneous activity that accompanied plate convergence and continental accretion. The abrupt change from orogenic calcalkaline igneous activity to post-collisional alkaline granite, followed by younger episodes of anorogenic emplacement, is remarkably similar to igneous events reported from pan-African mobile belts widespread throughout Africa. In addition, parts of the Dartmouth pluton exhibit features indicative of mixing and commingling of felsic and mafic melts that are associated with coevally formed mylonitic fabrics. Because these fabrics are conformable to those in adjacent gneisses, but discordant with Alleghanian fabrics in the nearby Carboniferous Narragansett basin, they represent some of the best candidates for pre-Alleghanian structures thus far identified in the southeastern New England Avalon zone.

  1. Zvyaginite, NaZnNb2Ti[Si2O7]2O(OH,F)3(H2O)4 + x ( x < 1), a new mineral of the epistolite group from the Lovozero Alkaline Pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Lykova, I. S.; Chukanov, N. V.; Yapaskurt, V. O.; Belakovskiy, D. I.; Zolotarev, A. A.; Zubkova, N. V.

    2014-12-01

    A new mineral, zvyaginite, a member of the epistolite group, has been found at Mt. Malyi Punkaruaiv, Lovozero Alkaline Complex, Kola Peninsula, Russia. It occurs in a hydrothermally altered peralkaline pegmatite and is associated with ussingite, microcline, aegirine, sphalerite, vigrishinite, and sauconite. Zvyaginite forms rectangular or irregular-shaped lamellae up to 0.1 × 1 × 2 cm in size when flattened [001]. The mineral is translucent to transparent and colorless, pearly-white, yellowish brownish, pale pink, or violet pink. The luster is nacreous on crystal faces and greasy on broken surfaces. Its Mohs' hardness is 2.5-3. Zvyaginite is brittle. The cleavage parallel to {001} is perfect. D meas = 2.88(3), D calc = 2.94 g/cm3. The mineral is optically biaxial (-), α = 1.626(5), β = 1.714(3), γ = 1.740(5), 2 V meas = 45(15)°, 2 V calc = 55°. The IR spectrum is given. Chemical composition is as follows (wt %; average of five point analyses; H2O was determined using the modified Penfield method): 4.74 Na2O, 0.22 K2O, 0.77 CaO, 1.36 MnO, 0.24 FeO, 9.61 ZnO, 0.19 Al2O3, 29.42 SiO2, 12.33 TiO2, 27.22 Nb2O5, 1.94 F, 12.65 H2O, -0.82 -O = F2, for a total of 99.87. The empirical formula calculated on the basis of Si + Al = 4 is: Na1.24K0.04Ca0.11Mn0.16Fe0.03Zn0.96Nb1.66Ti1.25(Si3.97Al0.03)Σ4O15.07(OH)2.10F0.83(H2O)4.64. The simplified formula is: NaZnNb2Ti[Si2O7]2O(OH,F)3(H2O)4 + x ( x < 1), Zvyaginite is triclinic, , a = 8.975(3), b = 8.979(3), c = 12.135(4) Å, α = 74.328(9)°, β = 80.651(8)°, γ = 73.959(8)°, V = 900.8(6) Å3, Z = 2. The strongest reflections in the X-ray powder pattern ( d, Å- I[ hkl]) are: 11.72-100[001], 5.83-40[002], 5.28-53[-1-11, 112], 4.289-86[200, 021], 3.896-36[-1-12, -201, 003, 022, 113], 2.916-57[310, 132, 004], 2.862-72[130, 312]. The model of the crystal structure was obtained on a single crystal, R = 0.159. Zvyaginite and epistolite are similar in the structure of the NbTiSiO motif, but differ from each other in composition

  2. Calc-alkaline plutonism along the Pacific rim of southern Alaska

    USGS Publications Warehouse

    Hudson, Travis

    1979-01-01

    Field, petrology, and age data on southern Alaska plutonic rocks now enable the delineation of eight calc-alkaline plutonic belts. These belts of plutons or batholithic complexes are curvilinear to linear and trend parallel or subparallel to the continental margin. The belts represent the principal loci of emplacement for plutons of specific ages and although there is spatial or temporal overlap in some cases, they are more commonly spatially and temporally distinct. Intermediate lithologies such as quartz diorite, tonalite, and granodiorite dominate in most of the Belts but granodiorite and granite characterize one. The belts are of Mesozoic or Cenozoic age and plutonism began in six of them at about 195, 175, 120, 75, 60, and 40 m.y. ago; age relations in two are poorly known. Recognition of the belts is important for future studies of regional geology, tectonism, and magmatism along the Pacific rim of southern Alaska.

  3. Middendorfite, K3Na2Mn5Si12(O,OH)36 · 2H2O, a new mineral species from the Khibiny pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Chukanov, N. V.; Dubinchuk, V. T.; Zadov, A. E.

    2007-12-01

    Middendorfite, a new mineral species, has been found in a hydrothermal assemblage in Hilairite hyperperalkaline pegmatite at the Kirovsky Mine, Mount Kukisvumchorr apatite deposit, Khibiny alkaline pluton, Kola Peninsula, Russia. Microcline, sodalite, cancrisilite, aegirine, calcite, natrolite, fluorite, narsarsukite, labuntsovite-Mn, mangan-neptunite, and donnayite are associated minerals. Middendorfite occurs as rhombshaped lamellar and tabular crystals up to 0.1 × 0.2 × 0.4 mm in size, which are combined in worm-and fanlike segregations up to 1 mm in size. The color is dark to bright orange, with a yellowish streak and vitreous luster. The mineral is transparent. The cleavage (001) is perfect, micalike; the fracture is scaly; flakes are flexible but not elastic. The Mohs hardness is 3 to 3.5. Density is 2.60 g/cm3 (meas.) and 2.65 g/cm3 (calc.). Middendorfite is biaxial (-), α = 1.534, β = 1.562, and γ = 1.563; 2 V (meas.) = 10°. The mineral is pleochroic strongly from yellowish to colorless on X through brown on Y and to deep brown on Z. Optical orientation: X = c. The chemical composition (electron microprobe, H2O determined with Penfield method) is as follows (wt %): 4.55 Na2O, 10.16 K2O, 0.11 CaO, 0.18 MgO, 24.88 MnO, 0.68 FeO, 0.15 ZnO, 0.20 Al2O3, 50.87 SiO2, 0.17 TiO2, 0.23 F, 7.73 H2O; -O=F2-0.10, total is 99.81. The empirical formula calculated on the basis of (Si,Al)12(O,OH,F)36 is K3.04(Na2.07Ca0.03)Σ2.10(Mn4.95Fe0.13Mg0.06Ti0.03Zn0.03)Σ5.20(Si11.94Al0.06)Σ12O27.57(OH)8.26F0.17 · 1.92H2O. The simplified formula is K3Na2Mn5Si12(O,OH)36 · 2H2O. Middenforite is monoclinic, space group: P21/ m or P21. The unit cell dimensions are a = 12.55, b = 5.721, c = 26.86 Å; β = 114.04°, V = 1761 Å3, Z = 2. The strongest lines in the X-ray powder pattern [ d, Å, ( I)( hkl)] are: 12.28(100)(002), 4.31(81)(11overline 4 ), 3.555(62)(301, 212), 3.063(52)(008, 31overline 6 ), 2.840(90)(312, 021, 30overline 9 ), 2.634(88)(21overline 9 , 1.0.overline 1 0

  4. The paleoproterozoic vurechuaivench layered Pt-bearing pluton, Kola Peninsula: New results of the U-Pb (ID-TIMS, SHRIMP) dating of baddeleytte and zircon

    NASA Astrophysics Data System (ADS)

    Rundkvist, T. V.; Bayanova, T. B.; Sergeev, S. A.; Pripachkin, P. V.; Grebnev, R. A.

    2014-01-01

    The Vurechuaivench layered PGE-bearing pluton (VP) is located in the central part of the Kola Peninsula, at the southeastern contact of the Monchegorsk layered complex with the Paleoproterozoic Imandra-Varzuga rift structure. The VP is composed of gabbronorites with a layered horizon of intercalated gabbronorites and anorthosites, containing sulfide and PGE-bearing mineralization. The U-Pb (ID-TIMS) age of baddeleytte from gabbronorite of the ore zone (sample M-42) was determined on a Finningan MAT-262 (RPQ) seven-channel mass-spectrometer in the Laboratory of Geochronology at the Geological Institute, Kola Scientific Center, Russian Academy of Sciences. Zircons from anorthosites and gabbronorites of the ore zone (samples B-1 and B-2, respectively) were studied on a SHRIMP-II secondary-ionic microprobe in the Center of Isotopic Studies of the Federal State Unitary Enterprise VSEGEI (St. Petersburg). The reliable age of formation of various VP rocks was determined by single grains of accessory baddeleytte and zircon based on additional studies of sample M-42 (2498.2 ± 6.7 Ma) and new studies of samples B-1 and B-2 (2507.9 ± 6.6 and 2504.8.4 Ma). The identical U-Pb ages of anorthosites and gabbronorites from the ore reef indicate that anorthosites are a dependent phase and were formed along with gabbronorites during the intrachamber melt differentiation and crystallization.

  5. Paleoproterozoic layered PGE-bearing Monchetundra pluton, Kola Peninsula: Sm-Nd age of metamorphic alteration of mafic rocks

    NASA Astrophysics Data System (ADS)

    Kunakkuzin, E. L.; Serov, P. A.; Bayanova, T. B.; Nerovich, L. I.; Borisenko, E. S.

    2015-09-01

    The aim of this work is Sm-Nd study of metamorphic alteration of massive gabbronorites from the Monchetundra pluton. The mafic rocks of the pluton are unevenly metamorphosed up to amphibolite facies with the formation of garnet, hornblende, and other minerals. The presence of garnet is a distinctive feature of this pluton in comparison with other Paleoproterozoic PGE-bearing plutons of the eastern part of the Baltic shield: Mt. General'skaya, Fedorovo-Pana, Imandra lopolith, and Monchepluton [9]. The degree of metamorphic alteration of rocks increases near the faults, the largest of which is Monchetundra fault separating the studied pluton from the Monchepluton. This fault was formed about 1.9-2.0 Ga ago according to Sm-Nd and Rb-Sr mineral isochrons for minerals from metagabbro-anorthosites of the M1 well.

  6. Mafic enclaves in the Wilson Ridge Pluton, northwestern Arizona: Implications for the generation of a calc-alkaline intermediate pluton in an extensional environment

    NASA Astrophysics Data System (ADS)

    Larsen, Lance L.; Smith, Eugene I.

    1990-10-01

    The Wilson Ridge pluton is an epizonal calc-alkaline pluton that formed about 13.5 Ma during a period of mid-Miocene extension. Faulting and erosional dissection provide a cross section of the pluton. The apex of the pluton, in the Boulder Wash area, Nevada, is composed of hypabyssal quartz monzonite and dacite. The base of the pluton is 20 km to the south where quartz monzodiorite, monzodiorite, and diorite are in low-angle intrusive contact with Precambrian basement. The pluton was separated from cogenetic volcanic rocks in the River Mountains by movement along the Saddle Island detachment fault at about 13.4 Ma. The River Mountains now lie 20 km to the west of the pluton. The Wilson Ridge pluton is composed of the Teakettle Pass suite consisting of foliated monzodiorite and quartz monzodiorite and unfoliated quartz monzonite and the older Horsethief Canyon diorite. Rocks of the pluton contain 2-4 modal percent sphene. Intermediate rocks of the Teakettle Pass suite contain abundant basaltic and diorite enclaves. Basaltic enclaves are lensoidal and pillow-like and commonly have crenulate and fine-grained margins. Enclaves are chemically similar to mafic dikes of the Wilson Ridge pluton and to cogenetic alkali basalt flows in the River Mountains. They probably represent blobs of mafic liquid that commingled and mechanically mixed with felsic magma to produce the intermediate rocks of the pluton. Basaltic enclaves commonly occur as inclusion-rich zones that represent synplutonic mafic dikes that were injected into a quartz monzonite host. Mafic magma was entrained and mechanically broken down by magmatic flow shear. A continuum in shape exists from enclaves that are bulbous and ellipsoidal to those that are thin, tabular mafic selvages and schlieren and ultimately to the mafic component in foliated quartz monzodiorite and monzodiorite. Diorite enclaves have angular contacts with host rocks and are interpreted as xenoliths. Field evidence and major and trace element

  7. Rare gas isotopes and parent trace elements in ultrabasic-alkaline-carbonatite complexes, Kola Peninsula: identification of lower mantle plume component

    NASA Astrophysics Data System (ADS)

    Tolstikhin, I. N.; Kamensky, I. L.; Marty, B.; Nivin, V. A.; Vetrin, V. R.; Balaganskaya, E. G.; Ikorsky, S. V.; Gannibal, M. A.; Weiss, D.; Verhulst, A.; Demaiffe, D.

    2002-03-01

    During the Devonian magmatism (370 Ma ago) ˜20 ultrabasic-alkaline-carbonatite complexes (UACC) were formed in the Kola Peninsula (north-east of the Baltic Shield). In order to understand mantle and crust sources and processes having set these complexes, rare gases were studied in ˜300 rocks and mineral separates from 9 UACC, and concentrations of parent Li, K, U, and Th were measured in ˜70 samples. 4He/ 3He ratios in He released by fusion vary from pure radiogenic values ˜10 8 down to 6 × 10 4. The cosmogenic and extraterrestrial sources as well as the radiogenic production are unable to account for the extremely high abundances of 3He, up to 4 × 10 -9 cc/g, indicating a mantle-derived fluid in the Kola rocks. In some samples helium extracted by crushing shows quite low 4He/ 3He = 3 × 10 4, well below the mean ratio in mid ocean ridge basalts (MORB), (8.9 ± 1.0) × 10 4, indicating the contribution of 3He-rich plume component. Magnetites are principal carriers of this component. Trapped 3He is extracted from these minerals at high temperatures 1100°C to 1600°C which may correspond to decrepitation or annealing primary fluid inclusions, whereas radiogenic 4He is manly released at a temperature range of 500°C to 1200°C, probably corresponding to activation of 4He sites degraded by U, Th decay. Similar 4He/ 3He ratios were observed in Oligocene flood basalts from the Ethiopian plume. According to a paleo-plate-tectonic reconstruction, 450 Ma ago the Baltica (including the Kola Peninsula) continent drifted not far from the present-day site of that plume. It appears that both magmatic provinces could relate to one and the same deep-seated mantle source. The neon isotopic compositions confirm the occurrence of a plume component since, within a conventional 20Ne/ 22Ne versus 21Ne/ 22Ne diagram, the regression line for Kola samples is indistinguishable from those typical of plumes, such as Loihi (Hawaii). 20Ne/ 22Ne ratios (up to 12.1) correlate well with 40

  8. Redox potential of the Khibiny magmatic system and genesis of abiogenic hydrocarbons in alkaline plutons

    NASA Astrophysics Data System (ADS)

    Ryabchikov, I. D.; Kogarko, L. N.

    2009-12-01

    The temperature and redox conditions of the crystallization of rocks from the Khibiny alkaline pluton have been estimated based on an analysis of coexisting magnetite, ilmenite, titanite, and pyroxene. Under redox conditions characteristic of the Khibiny Complex, CO2 is contained in fluid and carbonate anions are contained in melt at high temperature; then graphite is released and an appreciable amount of hydrocarbons appear at a lower temperature as products of reaction of graphite with fluid. Abiogenic hydrocarbons can arise in igneous complexes owing to a processes distinct from Fischer-Tropsch synthesis.

  9. Distinctly different parental magmas for calc-alkaline plutons and tholeiitic lavas in the central and eastern Aleutian arc

    NASA Astrophysics Data System (ADS)

    Cai, Yue; Rioux, Matthew; Kelemen, Peter B.; Goldstein, Steven L.; Bolge, Louise; Kylander-Clark, Andrew R. C.

    2015-12-01

    Cenozoic calc-alkaline plutons that comprise the middle crust of the central and eastern Aleutians have distinct isotopic and elemental compositions compared to Holocene tholeiitic lavas in the same region, including those from the same islands. Therefore the Holocene lavas are not representative of the net magmatic transfer from the mantle into the arc crust. Compared to the lavas, the Eocene to Miocene (9-39 Ma) intermediate to felsic plutonic rocks show higher SiO2 at a given Fe/Mg ratio, and have higher εNd-εHf values and lower Pb-Sr isotope ratios. However, the plutonic rocks strongly resemble calc-alkaline Holocene volcanics with more "depleted" isotope ratios in the western Aleutians, whose composition has been attributed to significant contributions from partial melting of subducted basaltic oceanic crust. These data could reflect a temporal variation of central and eastern Aleutian magma source compositions, from predominantly calc-alkaline compositions with more "depleted" isotope ratios in the Paleogene, to tholeiitic compositions with more "enriched" isotopes more recently. Alternatively, the differences between central Aleutian plutonic and volcanic rocks may reflect different transport and emplacement processes for the magmas that form plutons versus lavas. Calc-alkaline parental magmas, with higher SiO2 and high viscosity, are likely to form plutons after extensive mid-crustal degassing of initially high water contents. This conclusion has overarching importance because the plutonic rocks are chemically similar to bulk continental crust. Formation of similar plutonic rocks worldwide may play a key role in the genesis and evolution of continental crust.

  10. Minerals of zirconolite group from fenitized xenoliths in nepheline syenites of Khibiny and Lovozero plutons, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Menshikov, Yu. P.; Mikhailova, Yu. A.; Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Ivanyuk, G. Yu.

    2015-12-01

    Zirconolite, its Ce-, Nd-, and Y-analogs, and laachite, another member of the zirconolite group, are typomorphic minerals of the fenitized xenoliths in nepheline syenite and foidolite of the Khibiny-Lovozero Complex, Kola Peninsula, Russia. All these minerals are formed at the late stage of fenitization as products of ilmentie alteration under the effect of Zr-bearing fluids. The diversity of these minerals is caused by the chemical substitutions of Na and Ca for REE, Th, and U compensated by substitution of Ti and Zr for Nb, Fe and Ta, as well as by the redistribution of REE between varieties enriched in Ti (HREE) or Nb (LREE). The results obtained can be used in the synthesis of Synroc-type titanate ceramics assigned for the immobilization of actinides.

  11. Trace-element study and uranium-lead dating of perovskite from the Afrikanda plutonic complex, Kola Peninsula (Russia) using LA-ICP-MS

    NASA Astrophysics Data System (ADS)

    Reguir, Ekaterina P.; Camacho, Alfredo; Yang, Panseok; Chakhmouradian, Anton R.; Kamenetsky, Vadim S.; Halden, Norman M.

    2010-11-01

    The U-Pb geochronology of perovskite is a powerful tool in constraining the emplacement age of silica-undersaturated rocks. The trace-element and U-Pb isotopic compositions of perovskite from clinopyroxenite and silicocarbonatite from the Afrikanda plutonic complex (Kola, Russia) were determined by laser-ablation inductively-coupled mass-spectrometry (LA-ICP-MS). In addition, the Sr isotopic composition of perovskite was measured by isotope-dilution mass-spectrometry to better constrain the relations between its host rocks. Perovskite from the two rock types shows a different degree of enrichment in Na, Mg, Mn, Pb, Fe, Al, V, rare-earth elements, Zr, Hf, Th, U and Ta. The perovskite 87Sr/86Sr values are within analytical uncertainty of one another and fall within the range of mantle values. The 206Pb/238U ages (corrected for common lead using 207Pb-method) of perovskite from silicocarbonatite statistically yield a single population with a weighted mean of 371 ± 8 Ma (2σ; MSWD = 0.071). This age is indistinguishable, within uncertainty, to the clinopyroxenite weighted mean 206Pb/238U age of 374 ± 10 Ma (2σ; MSWD = 0.18). Our data are in good agreement with the previous geochronological study of the Afrikanda complex. The observed variations in trace-element composition of perovskite from silicocarbonatite and clinopyroxenite indicate that these rocks are not related by crystal fractionation. The Sr isotopic ratios and the fact that the two rocks are coeval suggest that they were either produced from a single parental melt by liquid immiscibility, or from two separate magmas derived at different degrees of partial melting from an isotopically equilibrated, but modally complex mantle source.

  12. The rare-metal ore potential of the Proterozoic alkaline ultramafic massifs from eastern part of the Baltic Shield in the Kola alkaline province.

    NASA Astrophysics Data System (ADS)

    Sorokhtina, Natalia; Kogarko, Lia

    2014-05-01

    The Kola Alkaline Province consists of intrusions of two main stages of the intraplate alkaline magmatism. The early stage of igneous activity occurred in Proterozoic 1.9 billion years ago, the next in Paleozoic at 380 million years. The Proterozoic alkaline magmatism produced Gremyakha-Vyrmes and Elet'ozero large alkaline-ultrabasic massifs, Tiksheozero carbonatite massif and numerous small syenite complexes. Paleozoic magmatism on Baltic Shield exhibited more widely, than Proterozoic. The world largest Khibiny and Lovozero alkaline intrusions, numerous alkaline-ultrabasic massifs with carbonanites, alkaline dike swarms and diatremes were formed. It is well known that carbonatites of Paleozoic alkaline-ultrabasic massifs contain large-scale deposits of rare-metal ores (Afanasiev et al., 1998). The metasomatic rocks on foidolites and carbonatites of Gremyakha-Vyrmes are final products of differentiation of Proterozoic alkaline-ultrabasic magma enriched in incompatible elements, including Nb and Zr similar to Paleozoic carbonatites. The massif Gremyakha-Vyrmes is one of the largest titanomagnetite-ilmenite deposits in Russia associated with ultrabasites. Our investigation showed that albite-microcline and aegirine-albite metasomatites formed rich rare-metal ores consisting of 3.2 wt. % Nb2O5 and 0.7 ZrO2. Zircon and pyrochlore-group minerals represent the main minerals of rare-metal ores. The following evolutionary sequences of pyrochlore group minerals has been observed: betafite or U pyrochlore - Na-Ca pyrochlore - Ba-Sr pyrochlore - "silicified" pyrochlore - Fe-Nb, Al-Nb silicates. Such evolution from primary Nb oxides to secondary silicates under low temperature hydrothermal conditions is similar to the evolution of rare metal phases in Paleozoic alkaline massifs analogous to Lovozero syenites and in carbonatites. The rare metal minerals of Gremyakha-Vyrmes crystallized in high alkaline hydrothermal environment at increased activity of Nb, Ta, Zr, U, Th and at

  13. Evolution and geochemistry of the Tertiary calc-alkaline plutons in the Adak Island region of the central Aleutian oceanic island arc

    NASA Astrophysics Data System (ADS)

    Kay, Suzanne; Citron, Gary P.; Kay, Robert W.; Jicha, Brian; Tibbetts, Ashley

    2014-05-01

    Calc-alkaline plutons are major crustal building blocks of continental margin mountain belts like the Mesozoic to Tertiary Andes and the Sierra Nevada, but are rare in oceanic island arcs. Some of the most calc-alkaline I-type island arc plutons are in the Central Aleutians with the most extreme signatures, as indicated by FeO/MgO ratios of < ~2 at 48-70% wt. % SiO2, in the ~10 km wide Oligocene Hidden Bay pluton on southern Adak Island and the 10 km wide Miocene Kagalaska pluton to the north on eastern Adak and the adjacent Kagalaska Island. Although small compared to most continental plutons, similarities in intrusive units, mineralogy and chemistry suggest common formation processes. The Aleutian calc-alkaline plutonic rocks mainly differ from continental plutons in having more oceanic like isotopic (87Sr/86Sr = 0.703-0.7033; Epsilon Nd = 9-7.8) and LIL (e.g., higher K/Rb) ratios. The Adak region plutons differ from Tertiary plutons on Unalaska Island further east in being more K-rich and in having a more oxidized and lower-temperature mineralogy. From a regional perspective, the Adak area plutons intrude Eocene/Oligocene Finger Bay Formation mafic volcanic and sedimentary rocks and postdate the small ~38 Ma tholeiitic Finger Bay pluton. The chemistry of these older magmatic rocks is basically similar to that of young Central Aleutian magmatic rocks with boninites and arc tholeiitic magmas seemingly being absent. The formation of the calc-alkaline plutons seems to require a sufficient crustal thickness, fluid concentration and contractional stress such that magma chambers can stabilize significant amounts of pargasitic hornblende. Seismic receiver function analyses (Janiszewski et al., 2013) indicate the modern Adak crust is ~ 37 km thick. Existing and new hornblende, plagioclase and biotite Ar/Ar ages from 16 Hidden Bay pluton and Gannet Lake stock gabbro, porphyritic diorite, diorite, granodiorite, leucogranodiorite and aplite samples range from 34.6 to 30

  14. Crystal accumulation and compositional trends in a calc-alkaline batholith: implications for correlation of plutonic and volcanic rocks

    NASA Astrophysics Data System (ADS)

    Barnes, C. G.; Coint, N.

    2013-12-01

    The Wooley Creek batholith is a tilted, calc-alkaline intrusive complex in the Klamath Mountain province, California, that can be divided into two main zones: lower (~159.2 × 0.2 Ma) and upper (~158.2 × 0.3 Ma), separated by a central transition zone. The lower zone consists of multiple intrusive units of gabbro through tonalite, with minor mafic synplutonic dikes and intrusive melagabbro and pyroxenite. Major and trace element data plot in two groups: a mafic group that encompasses pyroxenite to diorite, and a tonalitic group. For each group, Mg/Fe in augite was used to determine the approximate composition of equilibrium melt and then major element mass balance was used to calculate proportions of cumulate phases and melt. For the mafic group, no single parental magma can be identified, which is consistent with assembly via many magma batches. However, the most mafic rocks were derived from basaltic andesite magmas and represent 30 to 100% cumulate augite + opx × plagioclase × olivine. Interstitial melt in the tonalitic group was dacitic, and mass balance indicates from 30 to 80% cumulate pyroxenes + plagioclase × accessory apatite and Fe-Ti oxides. The parental magma was probably silicic andesite. The upper zone varies gradationally from structurally low quartz diorite to uppermost granite. Upper zone magmas ';leaked' to form dacitic to rhyodacitic ';roof dikes'. Previous work (Coint et al., Geosphere, in press) showed that the upper zone formed from an approximately homogeneous magma body and that compositional variation was related to upward percolation of melt. Mass balance supports this interpretation and indicates that (1) the parental magmas were andesitic, (2) structurally low rocks are 15 to 65 % cumulate hornblende + plagioclase × pyroxene, and (3) high-level granite and granodiorite are the fractionated products of this accumulation. These results show that the upper zone is a good example of fractional crystallization within a moderate

  15. Phosphoinnelite, Ba4Na3Ti3Si4O14(PO4,SO4)2(O,F)3, a new mineral species from peralkaline pegmatite of the Kovdor pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Chukanov, N. V.; Kulikova, I. M.; Belakovsky, D. I.

    2007-12-01

    Phosphoinnelite, an analogue of innelite with P > S, has been found in a peralkaline pegmatite vein crosscutting calcite carbonatite at the phlogopite deposit, Kovdor pluton, Kola Peninsula. Cancrinite (partly replaced with thomsonite-Ca), orthoclase, aegirine-augite, pectolite, magnesioarfvedsonite, golyshevite, and fluorapatite are associated minerals. Phosphoinnelite occurs as lath-shaped crystals up to 0.2 × 1 × 6 mm in size, which are combined typically in bunch-, sheaf-, and rosettelike segregations. The color is yellow-brown, with vitreous luster on crystal faces and greasy luster on broken surfaces. The mineral is transparent. The streak is pale yellowish. Phosphoinnelite is brittle, with perfect cleavage parallel to the {010} and good cleavage parallel to the {100}; the fracture is stepped. The Mohs hardness is 4.5 to 5. Density is 3.82 g/cm3 (meas.) and 3.92 g/cm3 (calc.). Phosphoinnelite is biaxial (+), α = 1.730, β = 1.745, and γ = 1.764, 2V (meas.) is close to 90°. Optical orientation is Z^c ˜ 5°. Chemical composition determined by electron microprobe is as follows (wt %): 6.06 Na2O, 0.04 K2O, 0.15 CaO, 0.99 SrO, 41.60 BaO, 0.64 MgO, 1.07 MnO, 1.55 Fe2O3, 0.27 Al2O3, 17.83 SiO2, 16.88 TiO2, 0.74 Nb2O5, 5.93 P2O5, 5.29 SO3, 0.14 F, -O=F2 = -0.06, total is 99.12. The empirical formula calculated on the basis of (Si,Al)4O14 is (Ba3.59Sr0.13K0.01)Σ3.73(Na2.59Mg0.21Ca0.04)Σ3.04(Ti2.80Fe{0.26/3+}Nb0.07)Σ3.13[(Si3.93Al0.07)Σ4O14(P1.11S0.87)Σ1.98O7.96](O2.975F0.10)Σ3.075. The simplified formula is Ba4Na3Ti3Si4O14(PO4,SO4)2(O,F)3. The mineral is triclinic, space group P overline 1 or P1. The unit cell dimensions are a = 5.38, b = 7.10, c = 14.76 Å; α = 99.00°, β = 94.94°, γ = 90.14°; and V = 555 Å3, Z = 1. The strongest lines of the X-ray powder pattern [ d, Å in ( I)( hkl)] are: 14.5(100)(001), 3.455(40)(103), 3.382(35)(0overline 2 2), 2.921(35)(005), 2.810(40)(1overline 1 4), 2.683(90)(200, overline 2 01), 2.133(80)(overline 2 overline

  16. A New Occurrence of Alkaline Magmatism on the Kola Peninsula: An Agpaitic Dyke in the Kandalaksha Region.

    NASA Astrophysics Data System (ADS)

    Akimenko, Mariya; Kogarko, Lia; Sorokhtina, Natalia; Kononkova, Natalia; Mamontov, Vladimir

    2015-04-01

    A new occurrence of alkaline dyke magmatism was discovered in 2010 during the geological works performed by the Murmansk Geological Prospecting Expedition in the "Mokhnatye Roga" area located 55 km to the southeast of the Kovdor massif (67°15' N, 31°30' E). The "Mokhnatye Roga" area is located in the Ensk segment of the northwestern part of the Belomorian mobile belt. We performed a complete petrological and geochemical description of the sections in Holes 19 and 24, which reveal one of the largest dykes in the area. The dyke, with a length of ≈4 km and a width of ≈160 m, has an eastern orientation with steep dipping (60°-90°) to the north. The thickness of Quaternary deposits ranges from 0.8 to 4.0 m; alkaline rocks occur in the range of 4.0-93.9 m being followed by host amphibole-biotite gneiss with interbeds of plagioamphibolite (AR2 mt) along the section. Among the major minerals of the dyke are the minerals of the lamprophyllite group (20-25 vol %), aegirine-augite (10-15 vol %), enigmatite (10-15 vol %), nepheline (10-15 vol %), orthoclase (15-20 vol %), alkaline amphibole (5-10 vol %), and astrophyllite (up to 5 vol %). The minor minerals are represented by shcherbakovite, sodalite, natrolite, barite, Mn carbonate, ilmenite, rutile, sphalerite, and goethite. The texture of the rock is porphyric: the groundmass is composed of finegranular nepheline and orthoclase, which are observed as individual large euhedral crystals as well. In addition, large phenocrysts are represented by the minerals of the lamprophyllite, enigmatite, pyroxene, and alkaline amphibole groups. Based on the generally accepted classifications [1], the studied agpaitic rock may be related to nepheline syenite; according to the mineral and chemical compositions, it is close to syenite of the Niva massif [2] located 35 km to the northeast from the "Mokhnatye Roga" area. Agpaitic syenite of the "Mokhnatye Roga" area is extremely enriched in dispersed and rare lithophile elements. The

  17. Mid-Neoproterozoic ridge subduction and magmatic evolution in the northeastern margin of the Indochina block: Evidence from geochronology and geochemistry of calc-alkaline plutons

    NASA Astrophysics Data System (ADS)

    Qi, Xuexiang; Santosh, M.; Zhao, Yuhao; Hu, Zhaocuo; Zhang, Chao; Ji, Fengbao; Wei, Cheng

    2016-04-01

    The mid-Neoproterozoic medium- to high-K calc-alkaline magmatic rocks in the northeastern margin of the Indochina block, SW China, provide important insights into the relationship of the Indochina block with the Gondwana supercontinent. Here we report zircon LA-ICP-MS U-Pb data from the early and late stage plutons which yield weighted mean 206Pb/238U ages of 765 Ma and 732-739 Ma suggesting mid-Neoproterozoic emplacement. The zircon εHf(t) values show a range of - 3.2 to + 2.4 (average + 0.1 ± 0.9) with TDMC of 1510 to 1870 Ma for the early plutons, and - 5.4 to + 5.1 (average + 2.1 to - 3.9) with TDMC of 1366 to 1985 Ma for late plutons. Both groups show similar geochemical characteristics including high Mg#, enrichment of LILE and LREE, slight negative Eu anomalies, and strongly negative Nb, Ta and Ti anomalies, with all the samples falling within the continental/island arc field in tectonic discrimination diagrams. These features suggest that the early and late stage magmas were produced by the mixing of mantle-derived magma and crust-derived magma in different proportion within an active continental margin, in subduction-related continental-arc tectonic setting. The linear zoning and roughly parallel distribution of the two generations of intrusions with a hiatus of 20 Ma might suggest an episode of ridge subduction with asthenosphere upwelling through the slab window that generated the second phase of plutons.

  18. A Pb isotope investigation of the Lovozero Agpaitic Nepheline Syenite, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Zartman, R. E.; Kogarko, L. N.

    2014-01-01

    For the first time Pb isotope composition was established in Lovozero rocks and raremetal ores, which is important for identifying their sources. The world's largest layered intrusion of agpaitic nepheline syenite-the Lovozero alkaline massif—is located near the center of the Kola Peninsula in Russia. This superlarge complex plutonic body hosts the economically important loparite and eudiallyte deposits [1]. These deposits contain immense resources of REE, Nb, Ta, Zr, and constitute a world class mineral district. The Lovozero massif belongs to the Kola ultramafic alkaline and carbonatitic province (KACP) of Devonian age. Previous bulk rock studies have shown that the initial Sr and Nd isotope ratios of Lovozero rocks plot in the depleted mantle quadrant of Sr-Nd diagrams [2]. More recently, Hf isotope data obtained by Kogarko et al. (3) confirm that the Lovozero and Khibina massifs with ɛHf between 6 and 8 are derived predominantly from a depleted mantle source. It was shown that Sr, Nd, and Hf abundances are significantly elevated in the Kola alkaline rocks, and thus their isotopic compositions are relatively insensitive to minor contamination by the overlying crustal rocks. By contrast, Pb in the KACP rocks is a much more sensitive indicator of a crustal component. In this paper we investigate the lead isotopic signature of all resentative types of Lovozero rocks (Table 1) in order to further characterize their mantle sources. The Lovozero massif consists of four intrusive phases. Rocks of phase I (mostly nepheline syenites) comprise about 5% of the total volume, phase II (urtites, foyaite, lujavrites) forms the main portion of the massif comprising 77% in volume, and phase III (eudialyte lujavrites) contributes about 18%. Country rocks are represented by Devonian effusive rocks and Archean gneisses.

  19. Burovaite-Ca, (Na,K)4Ca2(Ti,Nb)8[Si4O12]4(OH,O)8·12H2O, a new labuntsovite-group mineral species and its place in low-temperature mineral formation in pegmatites of the Khibiny pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Azarova, Yu. V.; Shlyukova, Z. V.; Zolotarev, A. A.; Organova, N. I.

    2009-12-01

    This paper presents data on burovaite-Ca, the first Ti-dominant member of the labuntsovite group with a calcium D-octahedron. The idealized formula of burovaite-Ca is (K,Na)4Ca2(Ti,Nb)8[Si4O12]4(OH,O)8 · 12H2O. The mineral has been found in the hydrothermal zone of aegirine-microcline pegmatite located in khibinite at Mt. Khibinpakhkchorr, the Khibiny pluton, Kola Peninsula, Russia. Radiaxial intergrowths of burovaite-Ca and labuntsovite-Mn associated with lemmleynite-Ba, analcime, and apophyllite have been identified in caverns within microcline. The mean composition of the mineral is as follows, wt %: 3.72 Na2O, 2.76 K2O, 4.22 CaO, 0.47 SrO, 0.23 BaO, 0.01 MnO, 0.30 Fe2O3, 0.14 Al2O3, 42.02 SiO2, 17.30 TiO2, 15.21 Nb2O5, 12.60 H2O (measured); the total is 98.98. Its empirical formula has been calculated on the basis of [(Si,Al)16O48]: {(Na3.10K1.07Ca0.37Sr0.04Ba0.04)4.62}(Ca1.28Zn0.01)1.29(Ti4.97Nb2.56Fe0.08Ta0.02)7.63(Si15.93Al0.07)16O48(OH6.70O0.93)7.63 · 12H2O. The strongest lines in the X-ray powder diffraction pattern of burovaite-Ca ( I-d Å] are as follows: 70-7.08, 40-6.39, 40-4.97, 30-3.92, 40-3.57, 100-3.25, 70-3.11, 50-2.61, 70-2.49, 40-2.15, 50-2.05, 70-1.712, 70-1.577, and 70-1.444. The structure of burovaite-Ca was solved by A.A. Zolotarev, Jr. The mineral is monoclinic, space group C2/ m. The unit-cell dimensions are a = 14.529(3), b = 14.203(3), c = 7.899(1), β = 117.37(1)°, V = 1447.57 Å3. Burovaite-Ca is an isostructural Ti-dominant analogue of karupmøllerite-Ca and gjerdingenite-Ca. Two stages of mineral formation—pegmatite proper and hydrothermal—have been recognized in the host pegmatite. The hydrothermal stage included K-Ba-Na, Na-K-Ca, and Na-Sr substages. Burovaite-Ca is related to the intermediate Na-K-Ca substage. At the first substage, labuntsovite-Mn and lemmleynite-Ba were formed, and tsepinite-Na, paratsepinite-Nd, and tsepinite-Sr were formed at the final substage. Thus, the sequence of crystallization of labuntsovite

  20. Geochemical features and age of baddeleyite from carbonatites of the Proterozoic Tiksheozero alkaline-ultramafic pluton, North Karelia

    NASA Astrophysics Data System (ADS)

    Rodionov, N. V.; Belyatsky, B. V.; Antonov, A. V.; Simakin, S. G.; Sergeev, S. A.

    2015-10-01

    On the basis of the local composition, baddeleyite grains that were less altered due to interaction with an alkaline melt and corresponded to the primary stage of crystallization of the intrusion were selected from the carbonatite intrusion of the Proterozoic polyphase Tiksheozero alkaline-ultramafic complex. The single age of carbonatite crystallization characterized of the bulk volume of the intrusion was estimated for the first time on the basis of 40 local U-Th-Pb (SHRIMP II) analyses of these grains. The overall concordant age of baddeleyite is 1994.8 ± 9.4 Ma, and the lower age limit of the polyphase complex formation is less than 1998.4 ± 3.5 Ma.

  1. A review of the occurrence, form and origin of C-bearing species in the Khibiny Alkaline Igneous Complex, Kola Peninsula, NW Russia

    NASA Astrophysics Data System (ADS)

    Nivin, V. A.; Treloar, P. J.; Konopleva, N. G.; Ikorsky, S. V.

    2005-11-01

    The Khibiny Complex hosts a wide variety of carbon-bearing species that include both oxidized and reduced varieties. Oxidised varieties include carbonate minerals, especially in the carbonatite complex at the eastern end of the pluton, and Na-carbonate phases. Reduced varieties include abiogenic hydrocarbon gases, particularly methane and ethane, dispersed bitumens, solid organic substances and graphite. The majority of the carbon in the Khibiny Complex is hosted in either the carbonatite complex or within the so-called "Central Arch". The Central Arch is a ring-shaped structure which separates khibinites (coarse-grained eudialite-bearing nepheline-syenites) in the outer part of the complex from lyavochorrites (medium-grained nepheline-syenites) and foyaites in the inner part. The Central Arch is petrologically diverse and hosts the major REE-enriched apatite-nepheline deposits for which the complex is best known. It also hosts zones with elevated hydrocarbon (dominantly methane) gas content and zones of hydrothermally deposited Na-carbonate mineralisation. The hydrocarbon gases are most likely the product of a series of post-magmatic abiogenic reactions. It is likely that the concentration of apatite-nepheline deposits, hydrocarbon gases and Na-carbonate mineralisation, is a function of long lived fluid percolation through the Central Arch. Fluid migration was facilitated by stress release during cooling and uplift of the Khibiny Complex. As a result, carbon with a mantle signature was concentrated into a narrow ring-shaped zone.

  2. Low-Sulfide PGE ores in paleoproterozoic Monchegorsk pluton and massifs of its southern framing, Kola Peninsula, Russia: Geological characteristic and isotopic geochronological evidence of polychronous ore-magmatic systems

    NASA Astrophysics Data System (ADS)

    Chashchin, V. V.; Bayanova, T. B.; Mitrofanov, F. P.; Serov, P. A.

    2016-01-01

    New U-Pb and Sm-Nd isotopic geochronological data are reported for rocks of the Monchegorsk pluton and massifs of its southern framing, which contain low-sulfide PGE ores. U-Pb zircon ages have been determined for orthopyroxenite (2506 ± 3 Ma) and mineralized norite (2503 ± 8 Ma) from critical units of Monchepluton at the Nyud-II deposit, metaplagioclasite (2496 ± 4 Ma) from PGE-bearing reef at the Vurechuaivench deposit, and host metagabbronorite (2504.3 ± 2.2. Ma); the latter is the youngest in Monchepluton. In the southern framing of Monchepluton, the following new datings are now available: U-Pb zircon ages of mineralized metanorite from the lower marginal zone (2504 ± 1 Ma) and metagabbro from the upper zone (2478 ± 20 Ma) of the South Sopcha PGE deposit, as well as metanorite from the Lake Moroshkovoe massif (2463.1 ± 2.7 Ma). The Sm-Nd isochron (rock-forming minerals, sulfides, whole-rock samples) age of orthopyroxenite from the Nyud-II deposit (2497 ± 36 Ma) is close to results obtained using the U-Pb method. The age of harzburgite from PGE-bearing 330 horizon reef of the Sopcha massif related to Monchepluton is 2451 ± 64 Ma at initial ɛNd =-6.0. The latter value agrees with geological data indicating that this reef was formed due to the injection of an additional portion of high-temperature ultramafic magma, which experienced significant crustal contamination. The results of Sm-Nd isotopic geochronological study of ore-bearing metaplagioclasite from PGE reef of the Vurechuaivench deposit (2410 ± 58 Ma at ɛNd =-2.4) provide evidence for the appreciable effect of metamorphic and hydrothermal metasomatic alterations on PGE ore formation. The Sm-Nd age of mineralized norite from the Nyud-II deposit is 1940 ± 32 Ma at initial ɛNd =-7.8. This estimate reflects the influence of the Svecofennian metamorphism on the Monchepluton ore-magmatic system, which resulted in the rearrangement of the Sm-Nd system and its incomplete closure. Thus, the new

  3. Vigrishinite, Zn2Ti4 - x Si4O14(OH,H2O,□)8, a new mineral from the Lovozero alkaline complex, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Britvin, S. N.; Zubkova, N. V.; Chukanov, N. V.; Bryzgalov, I. A.; Lykova, I. S.; Belakovskiy, D. I.; Pushcharovsky, D. Yu.

    2013-12-01

    A new mineral vigrishinite, epistolite-group member and first layer titanosilicate with species-defining Zn, was found at Mt. Malyi Punkaruaiv, in the Lovozero alkaline complex, Kola Peninsula, Russia. It occurs in a hydrothermally altered peralkaline pegmatite and is associated with microcline, ussingite, aegirine, analcime, gmelinite-Na, and chabazite-Ca. Vigrishinite forms rectangular or irregularly shaped lamellae up to 0.05 × 2 × 3 cm flattened on [001]. They are typically slightly split and show blocky character. The mineral is translucent to transparent and pale pink, yellowish-pinkish or colorless. The luster is vitreous. The Mohs' hardness is 2.5-3. Vigrishinite is brittle. Cleavage is {001} perfect. D meas = 3.03(2), D calc = 2.97 g/cm3. The mineral is optically biaxial (-), α = 1.755(5), β = 1.82(1), γ = 1.835(8), 2 V meas = 45(10)°, 2 V calc = 50°. IR spectrum is given. The chemical composition (wt %; average of 9 point analyses, H2O is determined by modified Penfield method) is as follows: 0.98 Na2O, 0.30 K2O, 0.56 CaO, 0.05 SrO, 0.44 BaO, 0.36 MgO, 2.09 MnO, 14.39 ZnO, 2.00 Fe2O3, 0.36 Al2O3, 32.29 SiO2, 29.14 TiO2, 2.08 ZrO2, 7.34 Nb2O5, 0.46 F, 9.1 H2O, -0.19 O=F2, total is 101.75. The empirical formula calculated on the basis of Si + Al = 4 is: H7.42(Zn1.30Na0.23Mn0.22Ca0.07Mg0.07K0.05Ba0.02)Σ1.96(Ti2.68Nb0.41Fe{0.18/3+}Zr0.12)Σ3.39(Si3.95Al0.05)Σ4 20.31F0.18. The simplified formula is: Zn2Ti4- x Si4O14(OH,H2O,□)8 ( x < 1). Vigrishinite is triclinic, space group P , a = 8.743(9), b = 8.698(9), c = 11.581(11)Å, α = 91.54(8)°, β = 98.29(8)°, γ = 105.65(8)°, V = 837.2(1.5) Å3, Z = 2. The strongest reflections in the X-ray powder pattern ( d, Å, - I[ hkl]) are: 11.7-67[001], 8.27-50[100], 6.94-43[01, 10], 5.73-54[11, 002], 4.17-65[020, 2, 200], and 2.861-100[30, 22, 004, 11]. The crystal structure model was obtained on a single crystal, R = 0.171. Vigrishinite and murmanite are close in the structure of the TiSiO motif, but

  4. Mineralogy, geochemistry, and genesis of high-alumina fenites of the Mont Saint-Hilaire alkaline pluton, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Yakovleva, O. S.; Pekov, I. V.; Horváth, L.; Bryzgalov, I. A.; Yapaskurt, V. O.; Guseva, E. V.

    2010-12-01

    High-alumina fenites in the Mont Saint-Hilaire alkaline complex, Québec, Canada, form bodies at the contact of peralkaline nepheline syenite. Fenites are subdivided into four types: corundum-spessartine-biotite-feldspar, muscovite-corundum-hercynite-biotite-feldspar, carbonated muscovite-biotite-hercynite-feldspar, and spessartine-hercynite-feldspar. Accessory minerals of the ilmenite-pyrophanite series, columbites, zircon, thorite, pyrrhotite, Fe, Mn, Mg, Ca, Ba, and REE carbonates, uedaite-(Ce), etc. are identified. Three stages are suggested in the formation of these rocks. In mineralogy and geochemistry, the Mont Saint-Hilaire high-alumina fenites are similar to Al-rich fenites replacing xenoliths in the Khibiny alkaline complex, Russia. In both cases, fenites are related to peralkaline rocks and replace high-alumina protoliths: granite at Mont Saint-Hilaire and metapelites in the Khibiny Mountains. These fenites are regarded as a specific type of fenites with rock-forming Mg-depleted hercynite.

  5. Early Paleozoic alkalic and calc-alkalic plutonism and associated contact metamorphism, central Virginia Piedmont

    USGS Publications Warehouse

    Pavlides, Louis; Arth, Joseph G.; Sutter, J.F.; Stern, T.W.; Cortesini, Henry, Jr.

    1994-01-01

    Early Paleozoic plutonism in the central Virginia Piedmont consists of the igneous Lahore Complex and Ellisville Pluton. The Lahore Complex consists of a small altered mafic pluton intruded by the shoshonitic, alkalic monzonites of the Lahore Pluton (-450 Ma) that, in turn, is intruded by the calc-alkaline, granodioritic Ellisville Pluton (-440 Ma). These plutons were emplaced at about 760aC at a depth of 12 to 18 km within greenschist-facies rocks and are enclosed by contact-metamorphosed rocks.

  6. Cymrite as an indicator of high barium activity in the formation of hydrothermal rocks related to carbonatites of the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Sorokhtina, N. V.; Chukanov, N. V.; Voloshin, A. V.; Pakhomovsky, Ya. A.; Bogdanova, A. N.; Moiseev, M. M.

    2008-12-01

    Cymrite, BaAl2Si2O8 · nH2O, is a rare mineral formed during low-grade dynamothermal metamorphism ( T = 250-300°C, P = 1-3 kbar). Cymrite has been described from many metasedimentary ores and hydrothermal rocks. In carbonatites, it has been found for the first time. Cymrite has been identified in the Kovdor and Seblyavr massifs, Kola Peninsula. In Kovdor, this mineral has been described from one of the hydrothermal veins cutting the pyroxenite-melilitite-ijolite complex at the Phlogopite deposit; cymrite is associated with thomsonite, calcite, and stivensite. In the Seblyavr pluton, cymrite occurs in thin veins of calcite carbonatite that cut pyroxenite contacting with ijolite. Cymrite from the Seblyavr pluton is associated with calcite, natrolite, pyrite, and chalcopyrite. The mineral is optically negative and uniaxial, with extinction parallel to elongation; ω ˜ 1.607(1). According to X-ray diffraction data, cymrite from Seblyavr is monoclinic, space group P1 m1; unit-cell dimensions are: a = 5.33, b = 36.96, c = 7.66 Å, β = 90°, V = 1510.55 Å3. According to the results of IR spectroscopy, in the series of samples from different massifs (in the running order Kovdor-Voishor-Seblyavr), the double-layer deformation is enhanced and accompanied by a decrease in the Si-O-Si angle and weakening of hydrogen bonds of interlayer water. The empirical formulas of cymrite calculated from electron microprobe analyses are Ba0.93-0.95Ca0.01-0.02K0.00-0.05Na0.02-0.04Al1.97-2.01Si1.99-2.03O8(H2O) and Ba1.00-1.02Ca0.00-0.01Sr0.00-0.01Fe0.00-0.01Al1.94-2.00Si1.98-2.03O8(H2O) at Seblyavr and Kovdor, respectively. Cymrite from the carbonatite massifs of the Kola Peninsula was formed under hydrothermal conditions at low temperature (200-300°C), high activity of Ba and Si, and high water pressure. At Kovdor, the mineral crystallized directly from the residual solution enriched in Ba. The sequence of mineral deposition is as follows: thomsonite-cymrite-calcite-stevensite. Cymrite

  7. Petrogenesis of collision-related plutonics in Central Anatolia, Turkey

    NASA Astrophysics Data System (ADS)

    Ilbeyli, N.; Pearce, J. A.; Thirlwall, M. F.; Mitchell, J. G.

    2004-02-01

    Central Anatolia exhibits good examples of calc-alkaline and alkaline magmatism of similar age in a collision-related tectonic setting (continent-island arc collision). In the Central Anatolia region, late Cretaceous post-collisional plutonic rocks intrude Palaeozoic-Mesozoic metamorphic rocks overthrust by Upper Cretaceous ophiolitic units to make up the Central Anatolian Crystalline Complex. In the complex, three different intrusive rock types may be recognised based on their geochemical characteristics: (i) calc-alkaline (Behrekdag, Cefalikdag, and Celebi); (ii) subalkaline-transitional (Baranadag); and (ii) alkaline (Hamit). The calc-alkaline and subalkaline plutonic rocks are metaluminous I-type plutons ranging from monzodiorite to granite. The alkaline plutonic rocks are metaluminous to peralkaline plutons, predominantly A-type, ranging from nepheline monzosyenite to quartz syenite. All intrusive rocks show enrichment in LILE and LREE relative to HFSE, and have high 87Sr/ 86Sr and low 143Nd/ 144Nd ratios. These characteristics indicate an enriched mantle source region(s) carrying a subduction component inherited from pre-collision subduction events. The tectonic discrimination diagram of Rb vs. (Y+Nb) suggests that the calc-alkaline, subalkaline, and alkaline plutonic rocks have been affected by crustal assimilation combined with fractional crystallisation processes. The coexistence of calc-alkaline and alkaline magmatism in the Central Anatolian Crystalline Complex may be attributed to mantle source heterogeneity before collision. The former carries a smaller intraplate component and pre-subduction enrichment compared to the latter. Either thermal perturbation of the metasomatised lithosphere by delamination of the thermal boundary layer (TBL), or removal of a subducted plate (slab breakoff) is the likely mechanism for the initiation of the post-collisional magmatism in the Complex.

  8. Trace Element Geochemistry including the HFSE in Magnetites of Calc-Alkaline Plutons: the Tanzawa Complex of the Izu-Bonin-Mariana Arc and the Ladakh Batholith Complex, NW Himalaya

    NASA Astrophysics Data System (ADS)

    Basu, A. R.; Ghatak, A.; Arima, M.; Srimal, N.

    2008-12-01

    In this study we attempt to contribute to the understanding of a prominent feature, namely the Nb-Ta depletion, in arc magmatic trace element geochemistry. Traditionally, this depletion is explained by residual mantle-wedge phases with Nb and Ta affinities, such as titaniferous ilmenite, rutile or titanite, or by an amphibole. Here we propose a mechanism long advocated to explain the calc-alkaline trend (Bowen vs. Fenner) in MgO-FeO (total Fe)-(Na2O + K2O) ternary diagram by early crystallization and separation of magnetite in subduction zone magmas associated with high oxygen fugacity environments. In support of our hypothesis we provide high-precision multiple trace element data, including the high field strength elements (HFSE), in separated magnetites and mafic mineral phases from mafic magmatic enclaves associated with tonalite suites of two different magmatic arcs - the Tanzawa Complex of the Izu-Tanzawa Collision Zone in Japan, and from the Ladakh Batholith Complex of NW Himalayas. The Tanzawa Complex is composed of diverse rock suites with SiO2 varying from 43 - 75 percent, ranging from hornblende gabbro through tonalite to leuco-tonalite. The geochemical characteristics of low K- tholeiites, enrichment of large ion lithophile elements (LILE), and depletion of HFSE in rocks of this plutonic complex are similar to those observed in the volcanic rocks of the IBM arc. The Ladakh batholith Complex is one of the granitic belts exposed north of the Indus-Tsangpo suture zone in Ladakh, representing calc-alkaline plutonism related to the subduction of the Neotethys floor in Late Cretaceous. This batholith comprises predominantly I-type granites with whole rock delta delta 18O values of 5.7-7.4 per mil, without major contribution from continental crustal material. We analyzed 22 trace elements by ICP-MS, including Nb-Ta-Hf-Zr, in separated magnetites from five gabbros of the Tanzawa tonalite-gabbro complex and from three tonalitic gabbros of the Ladakh batholith. In

  9. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  10. Alkaline igneous rocks

    SciTech Connect

    Fitton, J.G.; Upton, B.G.J.

    1987-01-01

    In this volume, an international team of scientists provides an up-to-date overview of the nature, origin, and evolution of alkaline magmas. Particular attention is paid to carbonatites, lamprophyres, and lamproites which are rock suites of current interest not recently reviewed elsewhere. Recent work on the classical alkaline provinces of East Africa, South Greenland, and the Kola Peninsula is included together with reviews of other areas of alkaline magmatism in North and South America, East Greenland, Europe, West Africa, and the ocean basins. Other papers discuss the impact of experimental isotopic and geochemical studies of the petrogenesis of alkaline rocks. This book will be of interest to petrologists and geochemists studying alkaline igneous rocks, and to other earth scientists as a reference on the rapidly expanding field of igneous petrology.

  11. Magma-mixing in the genesis of Hercynian calc-alkaline granitoids: an integrated petrographic and geochemical study of the Sázava intrusion, Central Bohemian Pluton, Czech Republic

    NASA Astrophysics Data System (ADS)

    Janoušek, Vojtěch; Braithwaite, Colin J. R.; Bowes, D. R.; Gerdes, Axel

    2004-10-01

    The Devonian-early Carboniferous (354.1±3.5 Ma: conventional zircon U-Pb age) Sázava intrusion (biotite-amphibole quartz diorite, tonalite and granodiorite) of the Central Bohemian Pluton (CBP) associated with bodies of (olivine, pyroxene-) amphibole gabbro, gabbrodiorite, (quartz) diorite and rare hornblendite, gives an opportunity for a comparative study of a rather shallow, calc-alkaline magma-mixing zone at two levels, separated by a vertical difference of approximately 1 km. The deeper section (Příbram) displays the direct evidence for the existence of a long-lived, periodically tapped and replenished, floored magma chamber (MASLI). The contacts between the subhorizontal sheet-like basic bodies and the surrounding, commonly cumulus-rich, Sázava granitoid, are arcuate, and cut by a series of veins and ascending pipes. Shallow-dipping swarms of strongly elongated and flow-aligned mafic microgranular enclaves (MME), concordant with the contacts of the basic bodies, are commonplace. The higher level (Teletín) section shows relatively independent basic intrusions, some of them distinctly hybrid in character and mainly of quartz dioritic composition, surrounded by relatively homogeneous, nearly cumulus-free Sázava tonalite rich in texturally variable MME. Larger quartz microdiorite bodies and the MME, both interpreted as hybrids, contain varying proportions of highly heterogeneous plagioclase megacrysts with complex zoning, particularly well shown by cathodoluminescence (CL). Most often the megacrysts have cores of labradorite-anorthite, partly resorbed and overgrown by andesine rims but some are strongly brecciated and fragments have been annealed by rim growth. Also characteristic are long prisms of apatite, oikocrysts of quartz and K-feldspar and zoned amphibole. The latter has brown pargasite and magnesiohastingsite cores, resorbed and overgrown by magnesiohornblende, compositionally similar to the amphibole in the Sázava tonalite. The brown cores are

  12. Petrology of the Plutonic Rocks of west-central Alaska

    USGS Publications Warehouse

    Miller, Thomas P.

    1970-01-01

    A series of plutons in west-central Alaska defines the Hogatza plutonic belt which extends for about 200 miles in an east-west direction from the northeastern Seward Peninsula to the Koyukuk River. The plutonic rocks have an aggregate area of about 1,200 square miles and their composition, distribution, and possible petrogenesis are discussed for the first time in this report. Field, petrographic and chemical data supported by K/Ar age dating indicate the plutonic rocks are divisible into two suites differing in age, location, and composition. The western plutons are mid-Cretaceous (~100 m.y.) in age and consist of a heterogeneous assemblage of monzonite, syenite, quartz monzonite. Associated with these granitic rocks is a group of alkaline sub-silicic rocks that forma belt of intrusive complexes extending for a distance of at least 180 miles from west-central Alaska to the Bering Sea. The complex at Granite Mountain shows a rare example of zoning from an alkaline rim to a quartz-bearing core. The occurrence of a similar complex at Cape Dezhnev on the easternmost tip of Siberia suggests the alkaline province may extend into Siberia. The easternmost plutons are Late Cretaceous (180 m.y.) in age and composed primarily of granodiorite and quartz monzonite similar to calc-alkaline plutons found throughout the North America Cordillera. The plutons are epizonal and intrude deformed but unmetamorphosed Lower Cretaceous andesitic volcanics and volcanic graywacke which constitute the highly mobile Yukon-Koyukuk volcanogenic province of west-central Alaska. No older rocks have been found within the confines of this vast tract; the occurrence of a bounding ophiolite sequence has lead to the suggestion that the province was formed by large-scale rifting and is underlain by oceanic crust. The possibility of no juvenile sialic crust over much of the area suggests that the potassium-rich magma now represented by the alkaline rocks originated in the mantle. The distribution of the

  13. Dyking Mechanism and Melting transfer, Misho granitoid Pluton (NW of Iran)

    NASA Astrophysics Data System (ADS)

    Mehri, M.; Mohssen, M.

    2009-04-01

    Misho granitoid pluton are exposed in NW of Misho elevation and SW of Marand depression (Nw of Iran). Mineralogical paragenesis of pluton contain unhedral to sub-hedral quartz, alkaline feldspar (microcline and sub-hedral to unhedral orthoclase), two type biotites, subhedral to euhedral plagioclase (oligoclase to albite), two type zircon, magmatic epidote, sphene and apatite. Pluton, samples show geochemical characteristic of syn - to post - collisional environment, s-type granite and allocktonous. Pluton located in faulted area with Paleozoic respect dating. Source rocks of Pluton are meta - graywake and meta - pelite mixed. One type of zircon and biotite are restitic. Pluton samples have textures that indicate the effect and evidence of pressure syn - crystallization. Field geological, mineralogical and geochemical characteristic of samples from this pluton associated with enclaves riched in mica and shapes of pluton suggest quick arising and dyking mechanism as main mechanism for melt transfer. This caused restitic zircon and biotite remained, there for main mechanism of arising and generation of this pluton are dyking with propagation of fractures so that diaprism process and mechanism have very low role and effect in emplacement and melt transfer of Misho granitoid. Key Words: Misho Pluton, Restitic biotite, Arising mechanism, Dyking

  14. Dyking Mechanism and Melting transfer, Misho granitoied Pluton (NW of Iran)

    NASA Astrophysics Data System (ADS)

    Mehri, M.; Mohssen, M.; Arezoo, S.; Aram, S.

    2009-04-01

    Misho granitoid pluton are exposed in NW of Misho elevation and SW of Marand depression (In Iran). Mineralogical paragenesis of pluton contain unhedral to sub â€" hedral quartz , alkaline feldspar (microcline and sub - hedral to unhedral orthoclase) , two type biotites , subhedral to euhedral plagioclase (oligoclase to albite) , two type zircon , magmatic epidote , sphene and apatite. Pluton ,s samples show geochemical charactrestic of syn â€" to post â€" collisional environment , s â€" type granite and allocktonous. Pluton located in faulted area with Paleozoic respect dating. Source rocks of Pluton are meta â€" graywake and meta â€" pelite mixed. One type of zircon and biotite are restitic. Pluton , s samples have textures that indicate the effect and evidence of pressure syn â€" crystallization. Field geological , mineralogical and geochemical characteristic of samples from this pluton associated with enclaves riched in mica and shapes of pluton suggest quick arising and dyking mechanism as main mechanism for melt transfer . this caused restitic zircon and biotite remained , There for main mechanism of arising and generation of this pluton are dyking with propagation of fractures so that diaprism process and mechanism have very low role and effect in emplacement and melt ,s transfer of Misho granitoid. Key Words: Misho Pluton , Restitic biotite , Arising mechanism , Dyking

  15. The superdeep well of the Kola Peninsula

    SciTech Connect

    Kozlovsky, Y.A.

    1986-01-01

    The structure of continental crusts is a subject of ever increasing importance in the geological sciences. Over 15 years ago, Soviet scientist began drilling a superdeep well on the Kola Peninsula near Murmansk. The well has reached a depth of 12 km and is thereby the deepest well in the world, yielding a vast amount of information on the structure of the continental crust. The geological, geophysical and technological data from the Kola well were initially published in a monographic account entitled ''Kol'skaja sverchglubokaja''. This English translation makes the results available to non-Soviet scientists as well.

  16. Structural setting and geochemistry of Devonian dikes in the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Terekhov, E. N.; Baluev, A. S.; Przhiyalgovsky, E. S.

    2012-01-01

    The structural setting and geochemistry of the Devonian dikes in the Kola Peninsula are considered. The alkaline dikes are controlled by rift- and drift-related structural elements. The first type of structures is exemplified by the Khibiny-Kontozero Fault Zone, which is regarded as a propagation zone of the East Barents Rift. The second type comprises Early Precambrian structural elements reactivated during Devonian drift of the East European Plate. Alkaline dikes occur in the ring structures at the ends of rifts and in the accommodation zones where the polarity of the main fault plane changes. These are the sites of accumulation and abrupt relaxation of tectonic stresses. Despite the significant differences in the petrography and chemistry of alkaline dikes, all of them are enriched in REE, apparently due to the elevated concentrations of these elements in the fluids. The dolerite dikes at the Murmansk Coast are located in the outer zone of the vast, concentrically zoned plateau basalt province with the East Barents Trough as its center. According to geophysical data, basaltic flows are suggested within this trough. The dolerite dikes increase in number in the inland propagation zone of the East Barents Trough extending in the Baltic Shield. The alkaline igneous rocks of the Kola Peninsula were formed under local compression at the periphery of the plateau basalt province.

  17. Late Jurassic plutonism in the southwest U.S. Cordillera

    USGS Publications Warehouse

    Barth, A.P.; Wooden, J.L.; Howard, K.A.; Richards, J.L.

    2008-01-01

    Although plate reconstructions suggest that subduction was an approximately steady-state process from the mid-Mesozoic through the early Tertiary, recent precise geochronologic studies suggest highly episodic emplacement of voluminous continental-margin batholiths in the U.S. Cordillera. In central and southern California and western Arizona, major episodes of batholithic magmatism are known to have occurred in Permian-Triassic, Middle Jurassic, and late Early to Late Cretaceous time. However, recent studies of forearc-basin and continental-interior sediments suggest that Late Jurassic time was probably also a period of significant magmatism, although few dated plutons of this age have been recognized. We describe a belt of Late Jurassic plutonic and hypabyssal rocks at least 200 km in length that extends from the northwestern Mojave Desert through the Transverse Ranges. The belt lies outboard of both the voluminous Middle Jurassic arc and the ca. 148 Ma Independence dike swarm at these latitudes. The plutons include two intrusive suites emplaced between 157 and 149 Ma: a calc-alkaline suite compositionally unlike Permian-Triassic and Middle Jurassic mon-zonitic suites but similar to Late Cretaceous arc plutons emplaced across this region, and a contemporaneous but not comagmatic alkaline suite. The Late Jurassic was thus a time of both tectonic and magmatic transitions in the southern Cordillera. ?? 2008 The Geological Society of America.

  18. Petrology of Quaternary volcanic rocks and related plutonic xenoliths from Gölcük volcano, Isparta Angle, Turkey: Origin and evolution of the high-K alkaline series

    NASA Astrophysics Data System (ADS)

    Platevoet, Bernard; Elitok, Ömer; Guillou, Hervé; Bardintzeff, Jacques-Marie; Yagmurlu, Fuzuli; Nomade, Sébastien; Poisson, André; Deniel, Catherine; Özgür, Nevzat

    2014-10-01

    The Quaternary volcanism of Isparta, south-western Anatolia, belongs to the post-collisional alkali-potassic to ultrapotassic magmatism, active since Miocene, from Afyon to Isparta. In the so-called Isparta Angle, the magmatism is contemporaneous with the Aegean extensional regime initiated during the Late Miocene and active throughout the Pliocene and Quaternary. The Gölcük volcano-forming stages consist of three main eruptive cycles: Cycle I comprising 200 m-thick pyroclastic flow deposits; Cycle II consisting of tephriphonolitic lava dome-flows extruded throughout the caldera; and Cycle III characterized by tuff-ring deposits related to the last phreatoplinian events. These late explosive events sampled plutonic xenoliths that allow to better constrain magma fractionation processes that operated at depth in the magma chamber. Magma evolution was first controlled by accumulation of clinopyroxene, phlogopite and apatite, then by phlogopite, amphibole and feldspars, with apatite, magnetite, titanite and zircon as accessories. Crystallization of clinopyroxene, phlogopite and amphibole probably controlled the silica-saturation trend of the whole series and faithfully reflect intensive H2O variations in the magma that were responsible of explosive cyclic events. The parental magma may have had a lamprophyric-tephritic composition. Trace element and isotope ratios indicate a prevalent asthenospheric source versus lithospheric one. Geochemical features, such as strong enrichment of LILE, REE, HFSE in the Gölcük magma point to the involvement of a asthenospheric OIB-type melt with a possible carbonatitic component, that interacted with remnants of the delaminated lithosphere during upwelling.

  19. Late Silurian plutons in Yucatan

    NASA Astrophysics Data System (ADS)

    Steiner, M. B.; Walker, J. Douglas

    1996-08-01

    U-Pb measurements of zircons from two composite plutons in the Maya Mountains of the Yucatan Block (Belize) give Late Silurian ages. Zircons from one of the five compositional phases of the Mountain Pine Ridge pluton yield an age of 418±3.6 Ma. A second compositional phase gives a minimum age of 404 Ma, and zircons from a third phase, although plagued with high common Pb, yield ages consistent with the other two. Zircons from one compositional phase of the Hummingbird-Mullins River pluton indicate an age of about 410-420 Ma. These data demonstrate that two of the three Maya Mountains plutons residing among the strata of the Late Pennsylvanian through Permian Santa Rosa Group are older than that sedimentation. Although the third pluton was not dated, both the similarity of sedimentary facies patterns adjacent to it to those adjacent to one of the plutons dated as Late Silurian and a published single Rb-Sr age of 428 ± 41 Ma suggest this third pluton also was emergent during Santa Rosa deposition. Thus the new U/Pb dates and other data suggest that all three Maya Mountains plutons pre-date Late Carboniferous sedimentation and that none intrude the Santa Rosa Group. Although very uniform ages of about 230 Ma amongst all plutons, derived from abundant earlier dating by the K-Ar system, led to the conclusion that intrusion mostly had occurred in the Late Triassic, the U-Pb ages (obtained from the same sites as the K-Ar dates) demonstrate that the K-Ar ages do not derive from a Late Triassic intrusive episode. The K-Ar dates probably are a signature of the rifting associated with Pangean breakup and formation of the Gulf of Mexico. In a reconstructed Pangea, the position of the Maya Mountains Late Silurian plutons suggests that the Late Silurian Acadian-Caledonian orogen of eastern North America extended through the region of the future Gulf of Mexico. Finally, the U-Pb ages of the Maya Mountains plutons are the same as those of a group of shocked zircons found in the

  20. Low-sulfide PGE ore in the Volchetundra gabbro-anorthosite pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Chashchin, V. V.; Petrov, S. V.

    2013-09-01

    The internal structure of the Volchetundra gabbro-anorthosite massif is considered, including localization of low-sulfide PGE mineralization and its mineralogy. The Volchetundra massif 24 km long and 0.5-4.0 km wide occupies the middle part of the Main Range complex, which extends for 75 km in the nearly meridional direction. The main and marginal zones are distinguished in the massif. The marginal zone 20-400 m wide extends along the entire eastern contact of the massif and is primarily composed of mediumgrained meso- and leucocratic norite, gabbronorite, plagioclasite, and less fequent orthopyroxenite. The main zone consists of coarse-grained leucogabbro and gabbronorite with an anorthosite zone in the axial part of the massif. The PGE mineralization of the Volchetundra massif is distinctly subdivided into two types substantially differing in localization, mineralogy, geochemistry, and economic importance. Mineralization of the first type is localized in the marginal zone and characterized by the highest resource potential. Mineralization hosted in the main zone belongs to the second type. The PGE ore of marginal zone is spatially and genetically related to the pyrite-pentlandite-chalcopyrite-pyrrhotite sulfide mineralization (1-5%) in the form of fine inequigranular interstitial disseminations, and less frequent larger grains and pockets localized within two ore zones each up to 2 km in extent. The thickness of separate mineralized layers varies from 0.5 to 3.0 m and up to 45 m in bulges. The average Pt + Pd grade is 1.37 gpt at Pd/Pt = 3.1. The mineralization of the second type has been penetrated by boreholes. Separate intersections do not correlate with one another and are limited in extent both along the strike and down the dip. The PGE mineralization is related to finely dispersed pentlandite-pyrite-pyrrhotite-chalcopyrite sulfides, sulfide emulsions, and less abundant stringer-disseminated sulfide ore. The orebodies vary from 2 to 7 m in thickness. The average Pt + Pd grade is 1.61 gpt; Pd/Pt = 1.3. The PGE mineralization includes 22 mineral species. PGE sulfides (cooperite-braggite-vysotskite; laurite and erlichmanite in insignificant amounts) are predominant. Bismuthotellurides (moncheite-kotulskite-merenskyite) and arsenides (sperrylite, palladoarsenite, arsenopalladinite, atheneite) are subordinate in abundance. In addition, sulfoarsenides (platarsite, hollingworthite), tellurides (telargpalite, sopcheite, keithconnite, melonite, hessite), paolovite, and Pt-Fe alloy have been identified. An admixture of native gold and electrum occur constantly.

  1. The Solarya Volcano-Plutonic Complex (NW Turkey): Petrography, Petrogenesis and Tectonic Implications

    NASA Astrophysics Data System (ADS)

    Ünal, Alp; Kamacı, Ömer; Altunkaynak, Şafak

    2014-05-01

    The post collisional magmatic activity produced several volcano-plutonic complexes in NW Anatolia (Turkey) during the late Oligocene- Middle Miocene. One of the major volcano-plutonic complexes, the Solarya volcano-plutonic complex is remarkable for its coeval and cogenetic plutonic (Solarya pluton), hypabysal and volcanic rocks of Early Miocene (24-21 Ma) age. Solarya pluton is an epizonal pluton which discordantly intruded into metamorphic and nonmetamorphic basement rocks of Triassic age. It is a N-S trending magmatic body covering an area of 220 km2,approximatelly 20 km in length and 10 km in width. Based on the field and petrographic studies, three main rock groups distinguished in Solarya pluton; K-feldspar megacrystalline granodiorite, microgranite-granodiorite and haplogranite. Porphyritic and graphic-granophyric textures are common in these three rock groups. Pluton contains magmatic enclaves and syn-plutonic dykes of dioritic composition. Hypabyssal rocks are represented by porphyritic microdiorite and porphyritic quartz-diorite. They form porphyry plugs, sheet inrusions and dykes around the pluton. Porphyrites have microcrystalline-cryptocrystalline groundmass displaying micrographic and granophyric textures. Petrographically similar to the hypabyssal rocks, volcanic rocks are formed from andesitic and dasitic lavas and pyroclastic rocks. Plutonic, hypabyssal and volcanic rocks of Solarya volcano-plutonic complex show similar major-trace element and Sr-Nd-Pb isotopic compositions, indicating common magmatic evolution and multicomponent melt sources including mantle and crustal components. They are mainly metaluminous, medium to high-K calc alkaline rocks and display enrichment in LILE and depletion in Nb, Ta, P and Ti. They have initial 87Sr/86Sr values of 0.70701- 0.70818 and 143Nd/144Nd values of 0.51241-0.51250. These geochemical characteristics and isotopic signatures are considered to reflect the composition of the magmas derived from a

  2. Cell-zonal textures of tinguaites from the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Voitsekhovsky, Y. L.; Shpachenko, A. K.; Skiba, V. I.

    Textures of tinguaite dykes cutting the alkaline Khibiny massif in the Kola Peninsula, Russia, are described. They are characterized by a combination of a fractal microfracture network dividing rock into pencil-like cells and of a concentric rhythmical zonation in almost all of them. The latter is formed by interchange of volatile-enriched and volatile-depleted mineral zones. The location of the textures only where dykes contact host khibinites appears to point out the contraction nature of the microfracture network. The cooling time calculated agrees well with this hypothesis. The zonation appears to have arisen through autometamorphic processes with two main competing factors, namely (a) overall cooling of the system and (b) periodic depletion of it in some elements, mainly Na and K. Another mechanism which may be applied to explain the zonation is the known Marangoni Instability effect at the early stage of evolution of the volatile-saturated phonolite melt. Thus, tinguaite textures are caused by nonspecific influences external to the system and may be regarded as an example of self-organization in nature.

  3. Late-stage sinking of plutons

    USGS Publications Warehouse

    Glazner, A.F.; Miller, D.M.

    1997-01-01

    Many granodiorite to diorite plutons in the Great Basin of western North America are surrounded by rim monoclines or anticlines that suggest relative downward movement of the plutons while wall rocks were hot and ductile. We propose that such plutons rise to a level of approximately neutral buoyancy and then founder as their densities increase ??? 40% during crystallization. Late-stage sinking of intermediate to mafic plutons should be common when wall rocks are rich in weak, low-density minerals such as quartz and calcite. Structures related to sinking will overprint those related to initial pluton emplacement and may be mistaken for regional tectonic structures.

  4. Evidence from the Farmington pluton for early Devonian subduction-related magmatism in the Carolina zone of central North Carolina

    NASA Astrophysics Data System (ADS)

    Esawi, E. K.

    2004-04-01

    The Concord plutonic suite consists of numerous gabbroic plutons scattered throughout the Carolina terrane with ages that cluster around 400 Ma. The Farmington pluton is located on the northeastern part of the Mocksville complex and consists mostly of gabbronorites and troctolites. Field, geochemical, and P-T studies of the Farmington gabbros suggest that the rocks are genetically related and formed by transitional to calc-alkaline differentiation of mafic magma. The pluton was formed in a moderate-pressure environment (˜6 kbar) and underwent limited differentiation after emplacement. The overall geological and geochemical features of the Farmington pluton are consistent with a transitional to arc origin. The Concord plutonic suite does not fit well in classical tectonothermal models suggested for the evolution of the Appalachian orogen. However, Field and geochemical data in this report and other data reported recently suggest that the origin of the Farmington pluton and possibly the Concord plutonic suite is that the suite represents a continuous to semi-continuous Taconian-Acadian magmatic event(s).

  5. Surface Ozone Dynamics in the Kola Peninsula Region

    NASA Astrophysics Data System (ADS)

    Beloglazov, M. I.; Karpechko, A. Yu.; Nikulin, G. N.; Roumjantsev, S. A.

    Measurements of surface ozone from the centre of the Murmansk Region (Apatity, Kola peninsula) and its southern part (Kovda, White Sea coast) give a picture of the behaviour of this air component on the Kola peninsula and surrounding vicinity. Simultaneous measurements in Apatity and Kovda have shown that the ozone concentration in Apatity is roughly twice as much as in Kovda. This fact may be explained by the local wind circulation and the presence of bromine near the coast of the Kola Peninsula. An inverse correlation is found between the ozone and nitrogen oxide concentrations from observations near motorways in Apatity. A decrease of nitrogen oxide concentration accompanies the growth of ozone on average. Thus, Apatity is a northern city in which the air pollution by traffic emissions decreases the ozone content.

  6. Mesoarchean Gabbroanorthosite Magmatism of the Kola Region

    NASA Astrophysics Data System (ADS)

    Kudryashov, N.; Mokrushin, A.

    2012-04-01

    The Kola peninsula is the region marked with development of anorthosite magmatism in the NE Baltic Shield. The Archaean gabbroanorthosites intrusions - Tsaginsky, Achinsky and Medvezhe-Schucheozersky - have the age of 2.7-2.6 Ga (Bayanova, 2004). The Patchemvarek and Severny gabbroanorthosites intrusions are located in the junction zone of the Kolmozero-Voronja greenstone belt and the Murmansk domain. Age data for sedimentaryvolcanogenic rocks of the Kolmozero-Voronja belt and Murmansk domain granitoids are 2.8-2.7 Ga. The gabbroanorthosites intrusions have more calcic composition (70-85% An) of normative plagioclase, and low contents of TiO2, FeO, and Fe2O3. In terms of chemical composition, the gabbroanorthosites of the studied massifs are close to the rocks of the Fiskenesset Complex (Greenland) and to the anorthosites of the Vermillion Lake Complex (Canada). U-Pb zircon dating established Mesoarchean ages of 29257 and 29358 Ma for the gabbroanorthosites of the Patchemvarek and Severny massifs, respectively. It was shown that the gabbroanorthosites of the studied massifs have fairly low REE contents (Cen = 2.2-4.2, Ybn = 1.6-2.6) and distinct positive Eu anomaly. Comagmatic ultrabasic differentiates have practically unfractionated REE pattern, low total REE contents (Cen = 1.2, Ybn = 1.1, La/Ybn = 1.32), and no Eu anomaly. The studied samples of the Archean gabbroanorthosites are characterized by positive "Nd= + 2.68 for the gabbroanorthosites of the Severny Massif and from + 2.77 to + 1.66 for the Patchemvarek Massif. The rocks of the Severny and Patchemvarek massifs has 87Sr/86Sri = 0.702048 and 87Sr/86Sri = 0.70258_8, respectively. The oldest U-Pb zircon ages for the gabbroanorthosites of the Patchemvarek and Severny massifs marking the Mesoarchean stage in the evolution of region. The differences in the initial 143Nd/144Nd ratios between the Neoarchean and the Mesoarchean gabbroanorthosites suggest the existence of two mantle sources. One of them produced

  7. The Fazenda Gavião granodiorite and associated potassic plutons as evidence for Palaeoproterozoic arc-continent collision in the Rio Itapicuru greenstone belt, Brazil

    NASA Astrophysics Data System (ADS)

    Costa, Felipe G.; Oliveira, Elson P.; McNaughton, Neal J.

    2011-08-01

    Several granitic plutons have intruded the Palaeoproterozoic Rio Itapicuru greenstone belt, São Francisco craton, Brazil, in the time interval 2163-2080 Ma, but their tectonic significance is poorly understood. The Fazenda Gavião granodiorite (FGG) is one of a set of plutons emplaced along the western boundary of the greenstone belt with Archaean migmatite-gneiss basement. The pluton is mostly composed of hornblende granodiorite, occasionally crosscut by syn-plutonic mafic dykes. The FGG is metaluminous, medium- to high-K calc-alkaline with relatively constant silica abundances (SiO2 ˜ 63-66 wt%), high Sr (900-800 ppm) and high Ba (1000-1500 ppm). The associated mafic dykes are ultrapotassic, with high abundances of Ba, Sr, MgO, Ni, Cr, and light rare earth elements, suggesting derivation from partial melts of an enriched mantle source. The FGG originated probably by fractional crystallization from a primitive K-rich mafic magma that interacted with crustal melts. Its zircon U-Pb SHRIMP age of 2106 ± 6 Ma indicates that the FGG is younger than the early (2163-2127 Ma) tonalite-trondhjemite-granodiorite (TTG) and calc-alkaline arc plutons of the greenstone belt, and is closely related in time and space with potassic to ultrapotassic plutons (ca. 2110-2105 Ma). The negative ɛNd(t) of FGG and coeval K-rich plutons of the Rio Itapicuru greenstone belt contrasts markedly with the positive ɛNd(t) of the older arc plutons, indicating a major change of isotope signatures in granites of the Rio Itapicuru greenstone belt with time. This isotope shift may be related to magma contamination with older continental material and/or derivation of the parental potassic magma from enriched lithospheric mantle sources. We suggest that the K-rich plutons were emplaced during or shortly after Palaeoproterozoic arc-continent collision.

  8. Distinctly different parental magmas for plutons and lavas in the central Aleutian arc

    NASA Astrophysics Data System (ADS)

    Cai, Y.; Rioux, M. E.; Kelemen, P. B.; Goldstein, S. L.; Bolge, L.; Kylander-Clark, A. R.

    2014-12-01

    While it is generally agreed that continental crust is generated by arc magmatism, average arc lavas are basaltic while the bulk continental crust is andesitic, and this has led to many models for secondary reprocessing of the arc crust in order to form continental crust. We report new data on calc-alkaline plutons in the central Aleutians showing that they have distinctly different sources compared to Holocene tholeiitic lavas. Therefore the lavas are not representative of the net magmatic transfer from the mantle into the arc crust. Eocene to Miocene (9-39 Ma) intermediate to felsic plutonic rocks from the central Aleutian arc show higher SiO2 at a given Mg#, higher ɛNd- and ɛHf-values, and lower Pb isotope ratios than Holocene volcanic rocks from the same region. Instead, the plutonic rocks resemble volcanics from the western Aleutians isotopically, and have chemical compositions similar to bulk continental crust. These data could reflect temporal variation of Aleutian magma source compositions, from Eocene-Miocene "isotopically depleted" and predominantly calc-alkaline to Holocene "isotopically enriched" and predominantly tholeiitic. Alternatively, they may reflect different transport and emplacement processes for the magmas that form plutons and lavas: calc-alkaline magmas with higher Si content and high viscosity may preferentially form plutons, perhaps after extensive mid-crustal degassing of initially high water contents. The latter case implies that the upper and middle arc crust is more like the calc-alkaline bulk composition of the continental crust than the lavas alone. Crustal reprocessing mechanisms that preserve upper and middle arc crust, while removing lower arc crust, can account for the genesis and evolution of continental crust. Since gabbroic lower arc crust extends from ca 20-40 km depth, and is density stable over most of this depth range, "delamination" of dense lithologies [1] may not be sufficient to accomplish this. Alternatively

  9. Oxygen isotopic compositions of Central Andean plutonic and volcanic rocks, latitudes 26°-29° south

    NASA Astrophysics Data System (ADS)

    Longstaffe, Frederick J.; Clark, Alan H.; McNutt, Robert H.; Zentilli, Marcos

    1983-07-01

    Oxygen isotope data are reported for 27 igneous rocks of Mesozoic to Quaternary age from the Central Andes. 26-29°S. The plutonic rocks, and most of the volcanics, have δ18O values between 6.2 and 8.3‰. The whole-rock δ 18O values show a weak correlation with initial 87Sr/ 86Sr data. This O-Sr array differs from documented trends for calc-alkaline plutonic suites from California, Scotland and northern Italy, but overlaps with data for volcanic and plutonic rocks from Ecuador, northern Chile and southern Perú. The oxygen isotope results indicate that the magmas evolved without significant contamination from supracrustal rocks (e.g., rocks that experienced 18O enrichment during surficial weathering). The available O, Sr and Pb isotopic data for these rocks are best explained by magma generation in the upper mantle or lower crust. From the Late Mesozoic on, the 87Sr/ 86Sr values were modified at depth by isotopic exchange between the magma and a continually thickening crust of plutonic rocks of Late Precambrian to early Mesozoic age.

  10. Technology for NPP decantate treatment realized at Kola NPP

    SciTech Connect

    Stakhiv, Michael; Avezniyazov, Slava; Savkin, Alexander; Fedorov, Denis; Dmitriev, Sergei; Kornev, Vladimir

    2007-07-01

    At Moscow SIA 'Radon' jointly with JSC 'Alliance Gamma', the technology for NPP Decantate Treatment was developed, tested and realized at Kola NPP. This technology consists of dissolving the salt residue and subsequent treatment by ozonization, separation of the deposits formed from ozonization and selective cleaning by ferro-cyanide sorbents. The nonactive salt solution goes to an industrial waste disposal site or a repository specially developed at NPP sites for 'exempt waste' products by IAEA classification. This technology was realized at Kola NPP in December 2006 year. At this time more than 1000 m{sup 3} of decantates log time stored are treated. It allows solving very old problem to empty decantates' tanks at NPPs in environmentally safe manner and with high volume reduction factor. (authors)

  11. Thermal evolution of plutons: a parameterized approach

    SciTech Connect

    Spera, F.

    1980-01-18

    A conservation-of-energy equation was derived for the spatially averaged magma temperature in a spherical pluton undergoing simultaneous crystallization and both internal (magma) and external (hydrothermal fluid) thermal convection. The model accounts for the dependence of magma viscosity on crystallinity, temperature, and bulk composition; it includes latent heat effects and the effects of different initial water concentrations in the melt, and quantitatively considers the role that large volumes of circulatory hydrothermal fluids play in dissipating heat. The nonlinear ordinary differential equation describing these processes was solved for a variety of magma compositions, initial temperatures, initial crystallinities, volume ratios of hydrothermal fluid to magma, and pluton sizes. These calculations are graphically summarized in plots of the average magma temperature versus time after emplacement. Solidification times, defined as the time necessary for magma to cool from the initial emplacement temperature to the solidus temperature vary as R/sup 1/ /sup 3/, where R is the pluton radius. The solidification time of a pluton with a radius of 1 kilometer is 5 x 10/sup 4/ years; for an otherwise identical pluton with a radius of 10 kilometers, the solidification time is approx. 10/sup 6/ years. The water content has a marked effect on the solidification time. A granodiorite pluton with a radius of 5 kilometers and either 0.5 or 4 percent (by weight) water cools in 3.3 x 10/sup 5/ or 5 x 10/sup 4/ years, respectively. Convection solidification times are usually but not always less than conduction cooling times. 2 figures.

  12. Petrology and radiogeology of the Stripa pluton

    SciTech Connect

    Wollenberg, H.; Flexser, S.; Andersson, L.

    1980-12-01

    Both the quartz monzonite and the metavolcanic leptite which it intruded are strongly fractured. Two stages of fracture filling are evident; an earlier stage encompassing quartz, sericite, feldspar, epidote, and chlorite, and a later stage dominated by carbonate minerals. The Stripa quartz monozite is chemically and mineralogically distinct from other plutons in the region. Muscovite is the predominant mica in the quartz monzonite; biotite has been altered to chlorite, hornblende is absent, and accessory minerals are scarce. In contrast, in other plutons in the Stripa region, biotite and hornblende are prominent mafic minerals and accessory minerals are abundant. The Stripa quartz monzonite is also considerably more radioactive than the the leptite and other plutons in the region. Uranium and thorium abundances are both approx. 30 ppM, considerably higher than in normal granitic rocks where the thorium-to-uranium ratio generally exceeds 2. Potassium-argon dating of muscovite from the Stripa quartz monzonite indicates that this rock may be older, at 1691 million years than granitic rock of the neighboring Gusselby and Kloten massifs, whose ages, based on K-Ar dating of biotite, are respectively 1604 and 1640 m.y. Heat flow and heat productivity considerations show that although Stripa quartz monzonite contains high abundances of radioelements, the pluton has little efect on the regional heat flow. If it occurs in a layered plutonic setting, it is not more than 1.5 km thick; otherwise it may comprise a stock, dike, or border phase that is relatively small compared with the large granitic plutons exposed in the region.

  13. Petrography and geochemistry of the Arroyo de la Virgen and Isla Mala plutons, southern Uruguay: Early proterozoic tectonic implications

    NASA Astrophysics Data System (ADS)

    Preciozzi, F.; Bourne, J. H.

    1992-10-01

    The Arroyo de la Virgen pluton (AVP) and the Isla Mala pluton (IMP) are relatively small zoned intrusions of Early Proterozoic age. Radiometric age determinations suggest that the IMP is a composite pluton. The composition of the AVP ranges from granodiorite to leucogranite, whereas that of the IMP ranges from hornblendite to leucogranite. Both intrusions feature hornblende (with relict clinopyroxene cores) and biotite as mafic minerals. Muscovite and garnet are present in the most evolved members of each suite. Development of secondary chlorite, epidote, and sericite is common. Quartz typically has undulose extinction. The plutons are massive except near the margins of the intrusion. Both intrusions feature a calc-alkaline chemistry, have peraluminous indices of approximately 1.0, and were emplaced at relatively high levels in the crust. Application of several tectonic discriminant diagrams suggests that the IMP formed in an active continental-margin type of tectonic environment, whereas the AVP is a subalkaline, post-orogenic pluton. The ages of the IMP leucogranite and the AVP are similar (2290 and 2225 Ma, respectively). The age of the IMP leucogranite represents the minimum reliable age of the principal metamorphic event in southern Uruguay. A number of small dikes were emplaced into both intrusions approximately 300 million years later and represent a distinct phase of intrusive activity in the region.

  14. Geochemistry of Mesozoic plutons, southern Death Valley region, California: Insights into the origin of Cordilleran interior magmatism

    USGS Publications Warehouse

    Ramo, O.T.; Calzia, J.P.; Kosunen, P.J.

    2002-01-01

    Mesozoic granitoid plutons in the southern Death Valley region of southeastern California reveal substantial compositional and isotopic diversity for Mesozoic magmatism in the southwestern US Cordillera. Jurassic plutons of the region are mainly calc-alkaline mafic granodiorites with ??Ndi of -5 to -16, 87Sr/86Sri of 0.707-0.726, and 206Pb/204Pbi of 17.5-20.0. Cretaceous granitoids of the region are mainly monzogranites with ??Ndi of -6 to -19, 87Sr/86Sri of 0.707-0.723, and 206Pb/204Pbi of 17.4-18.6. The granitoids were generated by mixing of mantle-derived mafic melts and pre-existing crust - some of the Cretaceous plutons represent melting of Paleoproterozoic crust that, in the southern Death Valley region, is exceptionally heterogeneous. A Cretaceous gabbro on the southern flank of the region has an unuasually juvenile composition (??Ndi -3.2, 87Sr/86Sri 0.7060). Geographic position of the Mesozoic plutons and comparison with Cordillera plutonism in the Mojave Desert show that the Precambrian lithosphere (craton margin) in the eastern Mojave Desert region may consists of two crustal blocks separated by a more juvenile terrane.

  15. Multiphase groundwater flow near cooling plutons

    USGS Publications Warehouse

    Hayba, D.O.; Ingebritsen, S.E.

    1997-01-01

    We investigate groundwater flow near cooling plutons with a computer program that can model multiphase flow, temperatures up to 1200??C, thermal pressurization, and temperature-dependent rock properties. A series of experiments examines the effects of host-rock permeability, size and depth of pluton emplacement, single versus multiple intrusions, the influence of a caprock, and the impact of topographically driven groundwater flow. We also reproduce and evaluate some of the pioneering numerical experiments on flow around plutons. Host-rock permeability is the principal factor influencing fluid circulation and heat transfer in hydrothermal systems. The hottest and most steam-rich systems develop where permeability is of the order of 10-15 m2. Temperatures and life spans of systems decrease with increasing permeability. Conduction-dominated systems, in which permeabilities are ???10-16m2, persist longer but exhibit relatively modest increases in near-surface temperatures relative to ambient conditions. Pluton size, emplacement depth, and initial thermal conditions have less influence on hydrothermal circulation patterns but affect the extent of boiling and duration of hydrothermal systems. Topographically driven groundwater flow can significantly alter hydrothermal circulation; however, a low-permeability caprock effectively decouples the topographically and density-driven systems and stabilizes the mixing interface between them thereby defining a likely ore-forming environment.

  16. Petrology and radiogeology of the Stripa pluton

    SciTech Connect

    Wollenberg, Harold; Flexser, Steve; Andersson, Lennart

    1980-12-01

    To better define the character of the rock encompassing the thermomechanical and hydrological experiments at the Stripa mine in central Sweden, and to help determine the size of the Stripa pluton, detailed studies were conducted of the petrology and radiogeology of the quartz monzonite and adjacent rocks. Petrologic studies emphasized optical petrography, with supplementary X-ray diffraction, X-ray fluorescence and microprobe analyses. Radiogeologic investigations were based primarily on surface and underground gamma-ray spectrometric measurements of uranium, thorium and potassium, supplemented by laboratory gamma spectrometric analyses and fission-track radiographic determinations of the locations and abundance of uranium in the rock matrix. Both the quartz monzonite and the metavolcanic leptite which it intruded are strongly fractured. Two stages of fracture filling are evident; an earlier stage encompassing quartz, sericite, feldspar, epidote, and chlorite, and a later stage dominated by carbonate minerals. The Stripa quartz monzonite is chemically and mineralogically distinct from other plutons in the region. Muscovite is the predominant mica in the quartz monzonite; biotite has been altered to chlorite, hornblende is absent, and accessory minerals are scarce. In contrast, in other plutons in the Stripa region biotite and hornblende are prominent mafic minerals and accessory minerals are abundant. The Stripa quartz monzonite is also considerably more radioactive than the leptite and other plutons in the region. Uranium and thorium abundances are both- 30 ppm, considerably higher than in "normal" granitic rocks where the thorium-to-uranium ratio generally exceeds 2. Potassium-argon dating of muscovite from the Stripa quartz monzonite indicates that this rock may be older, at 1691 million years than granitic rock of the neighboring Gusselby and Kloten massifs, whose ages, based on K-Ar dating of biotite, are respectively 1604 and 1640 m.y. Heat flow and heat

  17. Time of formation and genesis of yttrium-zirconium mineralization in the Sakharjok massif, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Vetrin, V. R.; Skublov, S. G.; Balashov, Yu. A.; Lyalina, L. M.; Rodionov, N. V.

    2014-12-01

    The Kola geotectonic province in the northeastern Fennoscandian Shield accommodates a significant number of alkaline rock massifs differing in age. They are of mantle and mantle-crustal origin (alkali and nepheline syenites, carbonatites) and related to crustal sources (Neoarchean alkali granites). Among them, the Neoarchean Sakharjok nepheline syenite massif is related to the oldest intrusions of this kind bearing yttrium-zirconium mineralization. The crystallization of alkali syenite pertaining to the first intrusive phase of the intrusive Sakharjok massif is dated to 2645 ± 7 Ma, and this implies that this syenite postdated alkali granites (2.66-2.67 Ga). To date the yttrium-zirconium ore, we applied the local U-Pb method to zircon crystals occurring in the mineralized block hosted in nepheline syenite. The earliest fragments of zircon crystallized 1832 ± 7 Ma ago; the age of metamorphism is estimated at 1784 ± 13 Ma. These dates indicate the Paleoproterozoic age of the yttrium-zirconium mineralization, which was formed as a product of fluid reworking of the Neoarchean nepheline syenite of the Sakharjok massif.

  18. Model of formation of the Khibiny-Lovozero ore-bearing volcanic-plutonic complex

    NASA Astrophysics Data System (ADS)

    Arzamastsev, A. A.; Arzamastseva, L. V.; Zhirova, A. M.; Glaznev, V. N.

    2013-09-01

    The paper presents the results of a study of the large Paleozoic ore-magmatic system in the northeastern Fennoscandian Shield comprising the Khibiny and Lovozero plutons, the Kurga intrusion, volcanic rocks, and numerous alkaline dike swarms. As follows from the results of deep drilling and 3D geophysical simulation, large bodies of rocks pertaining to the ultramafic alkaline complex occur at the lower level of the ore-magmatic system. Peridotite, pyroxenite, melilitolite, melteigite, and ijolite occupy more than 50 vol % of the volcanic-plutonic complex within the upper 15 km accessible to gravity exploration. The proposed model represents the ore-magmatic system as a conjugate network of mantle magmatic sources localized at different depth levels and periodically supplying the melts belonging to the two autonomous groups: (1) ultramafic alkaline rocks with carbonatites and (2) alkali syenites-peralkaline syenites, which were formed synchronously having a common system of outlet conduits. With allowance for the available isotopic datings and new geochronological evidence, the duration of complex formation beginning from supply of the first batches of melt into calderas and up to postmagmatic events, expressed in formation of late pegmatoids, was no less than 25 Ma.

  19. Geochemistry of a Pliocene-Pleistocene oceanic-arc plutonic complex, Guadalcanal

    USGS Publications Warehouse

    Chivas, A.R.; Andrew, A.S.; Sinha, A.K.; O'Neil, J.R.

    1982-01-01

    The Koloula Igneous Complex, on the island of Guadalcanal, consists of a low-K calc-alkaline sequence of 26 different intrusive phases. The major intrusions are characterized by K/Rb>400, Rb/Sr<0.06, ?? 18O of 5.7 to 7.2 and uniform 87Sr/86Sr of 0.70372. This article presents the first data describing oxygen and strontium isotopic behaviour within a plutonic suite that formed by crystal fractionation. ?? 1982 Nature Publishing Group.

  20. Apatite fission track thermochronology of Khibina Massif (Kola Peninsula, Russia): Implications for post-Devonian Tectonics of the NE Fennoscandia

    NASA Astrophysics Data System (ADS)

    Veselovskiy, Roman V.; Thomson, Stuart N.; Arzamastsev, Andrey A.; Zakharov, Vladimir S.

    2015-12-01

    The thermal history of the Kola Peninsula area of NE Fennoscandia remains almost fully unknown because of the absence of any thermochronological data such as apatite and/or zircon fission track or (Usbnd Th)/He ages. In order to fill this gap and to constrain the post-Devonian erosion and exhumation history of this region, we present the results of apatite fission track (AFT) dating of eleven samples selected from the cores taken from different depths of the northern part of the Khibina intrusive massif. The Rbsbnd Sr isochron age of this alkaline magmatic complex which is located at the center of Kola Peninsula is 368 + 6 Ma (Kramm and Kogarko, 1994). Samples were analyzed from depths between + 520 and - 950 m and yielded AFT ages between 290 and 268 Ma with an age uncertainty (1σ) of between ± 19 Ma (7%) and ± 42 Ma (15%). Mean track lengths (MTL) lie between 12.5 and 14.4 μm. Inverse time-temperature modeling was conducted on the age and track length data from seven samples of the Khibina massif. Thermal histories that best predict the measured data from three samples with the most reliable data show three stages: (1) 290-250 Ma-rapid cooling from > 110 °C to 70 °C/50 °C for lower/upper sample correspondingly; (2) 250-50 Ma-a stable temperature stage; (3) 50-0 Ma-slightly increased cooling rates down to modern temperatures. We propose that the first cooling stage is related to late-Hercynian orogenesis; the second cooling stage may be associated with tectonics accompanying with opening of Arctic oceanic basin. The obtained data show that geothermal gradient at the center of Kola Peninsula has remained close to the modern value of 20 °C/km for at least the last 250 Myr. AFT data show that the Khibina massif has been exhumed not more then 5-6 km in the last 290 Myr.

  1. Thermal maturation of incrementally assembled plutons

    NASA Astrophysics Data System (ADS)

    Davis, J.; Coleman, D. S.; Heizler, M. T.

    2009-12-01

    The Cretaceous zoned intrusive suites of the Sierra Nevada batholith (SNB) were each assembled over 8-11 million years through incremental amalgamation of sheeted intrusions. Emplacement as small sheet-like increments inhibits development of a voluminous zone of melt bearing rock; instead the active magma body represents only a small portion of the total volume intruded. Plutons formed incrementally will have a protracted thermal history (T-t) that can be elucidated using thermochronologic techniques yielding insights into the thermal evolution of the lithosphere at magma chamber-pluton scales. Thermal histories are derived for plutons from the dike-like John Muir Intrusive Suite (JMIS) and the laccolithic Mount Whitney Intrusive Suite (MWIS), both located in the eastern-central SNB, by correlating estimated zircon saturation and argon closure temperatures with U-Pb zircon and titanite, 40Ar/39Ar amphibole, biotite, and K-feldspar ages. Close agreement among zircon and hornblende ages indicate rapid cooling following intrusion. However, hornblende and biotite ages are separated by 6-9 million years indicating slow protracted cooling. We interpret these data to reflect the thermal maturation of an incrementally assembled magma system in which temperatures cycled between ~500-300°C for millions of years. Hornblende ages were not reset by younger intrusions, therefore maximum reheating temperatures did not exceed ~500°C for geologically significant durations. T-t cooling curves from the intrusive suites are used to calibrate finite difference numerical simulations of pluton assembly. Intrusion geometries are modeled (HEAT 3D, Wohletz, 2007) by stacking horizontal increments from the top-down and bottom-up and vertical increments are emplaced syntaxially and antitaxially and are designed to generate plutons of the approximate dimensions, depth of emplacement, and age range of the Sierran suites. Numerical simulations yield the following general observations: 1) an

  2. Petrogenesis of Mesoproterozoic granitic plutons, eastern Llano Uplift, central Texas, USA

    NASA Astrophysics Data System (ADS)

    Smith, R. K.; Gray, Walt; Gibbs, Tyson; Gallegos, M. A.

    2010-08-01

    The Llano Uplift of central Texas is a gentle structural dome exposing ˜ 1370 to 1230 Ma metaigneous and metasedimentary rocks of Grenville affinity along the southern margin of Laurentia. The metamorphic rocks were subsequently intruded by ˜ 1119 to 1070 Ma late syn- to post-tectonic granites collectively known as the Town Mountain Granite (TMG). The eastern most of the TMG, the Marble Falls (MF), Kingsland (KL), and Lone Grove (LG) plutons, are metaluminous to marginally peraluminous, high-K, calc-alkaline, ferroan, biotite-calcic amphibole granites [Fe/(Fe + Mg) = 0.71-0.92 and 0.78-0.91 for biotite and calcic amphibole, respectively] displaying distinct variation trends with increasing silica content. They are chemically and texturally zoned and have mineralogical and chemical characteristics similar to A-type granites; i.e., 1) Fe-rich biotites, calcic amphiboles, accessory fluorite, and sporadic rapakivi texture, 2) high K 2O (> 4 wt.%), 3) low Al 2O 3 (< 16 wt.%) and CaO (< 3 wt.%), 4) high Fe/(Fe + Mg), 5) enrichments in Zr, Nb, REE, Ga/Al, and 6) depleted Eu. However, in contrast to typical A-type granites (having low Sr and Ba) the MF, KL,and LG plutons are enriched in Sr and Ba; i.e., up to 229 ppm and 1090 ppm, respectively. On granite discrimination diagrams [(K 2O + Na 2O)/CaO vs. Zr + Nb + Ce + Y (ppm) and Zr (ppm) vs. Ga/Al*10,000] the KL and MF plutons plot within the A-type field, whereas the LG pluton compositions are divided between A-type and fractionated granite fields (I-, S- and M-types). On tectonic discrimination diagrams (Y vs. Nb ) the MF and KL granites plot in the "within-plate" granite field, but the LG pluton plots across several fields including "within-plate" and "volcanic arc plus syn-collisional" fields. Consequently the tectonic classification on a geochemical basis for the LG pluton is unclear. Based on thermal metamorphic mineral assemblages, normative Q-Ab-Or plots, and Q-Ab-Or-H 2O experimental data (Johannes and Holtz

  3. Effect of dehusked Garcinia kola seeds on the overall pharmacokinetics of quinine in healthy Nigerian volunteers.

    PubMed

    Igbinoba, Sharon I; Onyeji, Cyprian O; Akanmu, Moses A; Soyinka, Julius O; Pullela, Srirama Sarma V V; Cook, James M; Nathaniel, Thomas I

    2015-03-01

    We investigated the effect of concurrent ingestion of Garcinia kola seed on the pharmacokinetics of quinine. In a randomized crossover study, 24 healthy Nigerian volunteers were assigned into 2 groups (A and B; n = 12 per group) on the basis of G. kola dose orally ingested. Each subject received 600 mg quinine sulfate before and after ingesting 12.5 g of G. kola once daily for 7 days (group A) or 12.5 g twice daily for 6 days and once on the seventh day (group B). Blood samples were collected and analyzed for plasma quinine and its metabolite (3-hydroxyquinine) using a validated high performance liquid chromatography method. Concurrent administration of quinine with G. kola reduced quinine tmax by 48% (group A), mean Cmax by 19% and 26% in groups A and B, respectively, and slight reduction in mean AUC0- ∞ of quinine in both groups. 3-hydroxyquinine Cmax also reduced by 29% and 32%; AUC0-∞ by 13% and 9%, respectively. The point estimates of the T/R ratio of the geometric means for all Cmax obtained and only the AUC0-∞ at a higher dose of G. kola were outside the 80%-125% bioequivalence range. In conclusion, an herb-drug interaction was noted with concurrent quinine and G. kola administration. PMID:25328082

  4. MEASUREMENTS OF THE CONFINEMENT LEAKTIGHTNESS AT THE KOLA NUCLEAR POWER STATION (UNIT 2) IN RUSSIA

    SciTech Connect

    GREENE,G.A.; GUPPY,J.G.

    1998-08-01

    This is the final report on the INSP project entitled, ``Kola Confinement Leaktightness'' conducted by BNL under the authorization of Project Work Plan WBS 1.2.2.1. This project was initiated in February 1993 to assist the Russians to reduce risks associated with the continued operation of older Soviet-designed nuclear power plants, specifically the Kola VVER-440/230 Units 1 and 2, through upgrades in the confinement performance to reduce the uncontrolled leakage rate. The major technical objective of this-project was to improve the leaktightness of the Kola NPP VVER confinement boundaries, through the application of a variety of sealants to penetrations, doors and hatches, seams and surfaces, to the extent that current technology permitted. A related objective was the transfer, through training of Russian staff, of the materials application procedures to the staff of the Kola NPP. This project was part of an overall approach to minimizing uncontrolled releases from the Kola NPP VVER440/230s in the event of a serious accident, and to thereby significantly mitigate the consequences of such an accident. The US provided materials, application technology, and applications equipment for application of sealant materials, surface coatings, potting materials and gaskets, to improve the confinement leaktightness of the Kola VVER-440/23Os. The US provided for training of Russian personnel in the applications technology.

  5. Effect of dehusked Garcinia kola seed on the overall pharmacokinetics of quinine in healthy Nigerian volunteers

    PubMed Central

    Igbinoba, Sharon I.; Onyeji, Cyprian O.; Akanmu, Moses A.; Soyinka, Julius O.; Pullela, Srirama Sarma V.V; Cook, James M.; Nathaniel, Thomas I.

    2016-01-01

    We investigated the effect of concurrent ingestion of Garcinia kola seed on the pharmacokinetics of quinine. In a randomized crossover study, 24 healthy Nigerian volunteers were assigned into two groups (A and B; n = 12 per group) on the basis of G. kola dose orally ingested. Each subject received 600mg quinine sulphate before and after ingesting 12.5g of G. kola once daily for seven days (Group A) or 12.5g twice daily for six days and once on the seventh day (Group B). Blood samples were collected and analyzed for plasma quinine and its metabolite, (3-hydroxyquinine) using a validated HPLC method. Concurrent administration of quinine with G. kola reduced quinine tmax by 48% (group A), mean Cmax by 19% and 26% in groups A and B, and slight reduction in mean AUC0–∞ of quinine in both groups. 3-hydroxyquinine Cmax also reduced by 29% and 32%; AUC0–∞ by 13% and 9% respectively. The point estimates of the T/R ratio of the geometric means for all Cmax obtained and only the AUC0–∞ at a higher dose of G. kola were outside the 80–125% bioequivalence range. In conclusion, an herb-drug interaction was noted with concurrent quinine and G. kola administration. PMID:25328082

  6. Petrology of Aztec Wash pluton, Eldorado Mountains, southern Nevada

    SciTech Connect

    Falkner, C.M.; Miller, C.F. ); Wooden, J.L. )

    1993-04-01

    Aztec Wash pluton, a 50 km[sup 2] intrusive complex in the northern Eldorado Mountains, was emplaced ca. 16 Ma (Faulds et al., 1990) during extension within the Colorado River Corridor. The pluton displays extreme compositional variability, ranging from olivine gabbro (ca. 50 wt% SiO[sub 2]) to highly evolved aplite (76% SiO[sub 2]). Most of the intrusion is medium grained, homogeneous granite (ca. 72% SiO[sub 2]), but 1/3 is highly heterogeneous and dominated by mafic to intermediate rocks; a 6 [times] 3km, N-S mafic zone almost bisects the pluton. Well-displayed magma mingling and late mafic and felsic dikes verify the coexistence of mafic and felsic melts. Hornblende barometry indicates that the entire exposed portion of Aztec Wash pluton was emplaced at very shallow depth (pluton has undergone little tilting. Mafic dikes that preceded emplacement of the pluton are variably dipping and in some cases sub horizontal, possibly suggesting a more complex pre-pluton deformational history. The authors propose the following emplacement history for Aztec Wash pluton: felsic magma intruded shallow levels of crust; the base of the magma chamber was intruded by basalt; after the upper portion of the initial magma was largely crystallized, basalt ascended into, perhaps remobilized, and mingled with felsic magma; this ascent may have been facilitated by E-W extension of the crystallizing pluton; more discrete syn- to post-pluton, mafic to felsic dikes mark additional intrusive pulses triggered by basalt intrusion and extensional fracturing. Field relations suggest that the mingling led to mixing in both the main units and the late dikes, but geochemical data indicate that mixing, if it occurred, was not a simple 2-end member process.

  7. Discrimination of alkalinity in granitoid Rocks: A potential TIMS application

    NASA Technical Reports Server (NTRS)

    Ruff, Steven W.

    1995-01-01

    In mineral exploration, the ability to distinguish and map petrochemical variations of magmatic rocks can be a useful reconnaissance tool. Alkalinity is one such petrochemical parameter and is used in the characterization of granitoid rocks. In quartz normative plutonic rocks, alkalinity is related to the composition and abundance of feldspars. Together with quartz abundance, knowledge of feldspar modes allows the classification of these igneous rocks according to the Streckeisen diagram. Alternative classification schemes rely on whole rock geochemistry instead of mineral identifications. The relative ease of obtaining whole rock analyses means that geochemical classifications tend to be favored in exploration geology. But the technique of thermal infrared spectroscopy of rocks yields information on mineralogy and is one that can be applied remotely. The goal of the current work then is to establish whether data from TIMS can be used to distinguish the mineralogical variations that relate to alkalinity. An ideal opportunity to test this thesis arises from the work presented in a paper by Dewitt (1989). This paper contains the results of mapping and analysis of Proterozoic plutonic rocks in north-central Arizona. The map resulting from this work delineates plutons according to alkalinity in an effort to establish a trend or polarity in the regional magmatism. Also contained within this paper are brief descriptions of the mineralogy of half of the region's plutons. This combination of mineralogical and geochemical information was the rationale behind choosing this area as a site for TIMS over flights. A portion of the region centered on the northern Bradshaw Mountains was selected because it contains plutons of all three alkalinity classifications (alkali-calcic, calc-alkalic, and calic) present on DeWitt's map within a relatively small area. The site was flown in August of 1994 and the data received a few days before the writing of this manuscript. Most of this

  8. Transformation of the chemical composition of the waters of small lakes on Kola Peninsula owing to a decrease in technogenic air pollution and to climate warming

    NASA Astrophysics Data System (ADS)

    Moiseenko, T. I.; Bazova, M. M.; Efimova, L. E.

    2014-05-01

    The emission of sulfur dioxide and metals from copper-nickel melting plants on Kola Peninsula (Russia) decreased pronouncedly over the last two decades. The decrease in the sulfate content and increase in the acid-neutralizing capability of waters were proven on the basis of the data of surveys on 75 small lakes repeated once every five years from 1990 to 2010. The variations of other parameters of the chemical composition of the waters of small lakes depend on the geological and landscape conditions of the formation of waters. The alkalinity and pH values increased in 46% of the lakes; 24% of them showed a further decrease of these parameters; and no reliable changes were traced in 31% of the lakes. The concentrations of Cu and Ni in the lacustrine water decreased 5-to 10-fold over the last two decades.

  9. Intrusive rocks and plutonic belts of southeastern Alaska, U.S.A.

    USGS Publications Warehouse

    Brew, David A.; Morrell, Robert P.

    1983-01-01

    About 30 percent of the 175,000-km2 area of southeastern Alaska is underlain by intrusive igneous rocks. Compilation of available information on the distribution, composition, and ages of these rocks indicates the presence of six major and six minor plutonic belts. From west to east, the major belts are: the Fairweather-Baranof belt of early to mid-Tertiary granodiorite; the Muir-Chichagof belt of mid-Cretaceous tonalite and granodiorite; the Admiralty-Revillagigedo belt of porphyritic granodiorite, quartz diorite, and diorite of probable Cretaceous age; the Klukwan-Duke belt of concentrically zoned or Alaskan-type ultramafic-mafic plutons of mid-Cretaceous age within the Admiralty-Revillagigedo belt; the Coast Plutonic Complex sill belt of tonalite of unknown, but perhaps mid-Cretaceous, age; and the Coast Plutonic Complex belt I of early to mid-Tertiary granodiorite and quartz monzonite. The minor belts are distributed as follows: the Glacier Bay belt of Cretaceous and(or) Tertiary granodiorite, tonalite, and quartz diorite lies within the Fair-weather-Baranof belt; layered gabbro complexes of inferred mid-Tertiary age lie within and are probably related to the Fairweather-Baranof belt; the Chilkat-Chichagof belt of Jurassic granodiorite and tonalite lies within the Muir-Chichagof belt; the Sitkoh Bay alkaline, the Kendrick Bay pyroxenite to quartz monzonite, and the Annette and Cape Fox trondhjemite plutons, all interpreted to be of Ordovician(?) age, together form the crude southern southeastern Alaska belt within the Muir-Chichagof belt; the Kuiu-Etolin mid-Tertiary belt of volcanic and plutonic rocks extends from the Muir-Chichagof belt eastward into the Admiralty-Revillagigedo belt; and the Behm Canal belt of mid- to late Tertiary granite lies within and next to Coast Plutonic Complex belt II. In addition, scattered mafic-ultramafic bodies occur within the Fairweather-Baranof, Muir-Chichagof, and Coast Plutonic Complex belts I and II. Palinspastic

  10. The chemical and isotopic differentiation of an epizonal magma body: Organ Needle pluton, New Mexico

    USGS Publications Warehouse

    Verplanck, P.L.; Farmer, G.L.; McCurry, M.; Mertzman, S.A.

    1999-01-01

    Major and trace element, and Nd and Sr isotopic compositions of whole rocks and mineral separates from the Oligocene, alkaline Organ Needle pluton (ONP), southern New Mexico, constrain models for the differentiation of the magma body parental to this compositionally zoned and layered epizonal intrusive body. The data reveal that the pluton is rimmed by lower ??(Nd) (~-5) and higher 87Sr/86Sr (~0.7085) syenitic rocks than those in its interior (??(Nd) ~ 2, 87Sr/86Sr ~0.7060) and that the bulk compositions of the marginal rocks become more felsic with decreasing structural depth. At the deepest exposed levels of the pluton, the ??(Nd)~-5 lithology is a compositionally heterogeneous inequigranular syenite. Modal, compositional and isotopic data from separates of rare earth element (REE)-bearing major and accesory mineral phases (hornblende, titanite, apatite, zircon) demonstrate that this decoupling of trace and major elements in the inequigranular syenite results from accumulation of light REE (LREE)-bearing minerals that were evidently separated from silicic magmas as the latter rose along the sides of the magma chamber. Chemical and isotopic data for microgranular mafic enclaves, as well as for restite xenoliths of Precambrian granite wall rock, indicate that the isotopic distinction between the marginal and interior facies of the ONP probably reflects assimilation of the wall rock by ??(Nd) ~-2 mafic magmas near the base of the magma system. Fractional crystallization and crystal liquid separation of the crystally contaminated magma at the base and along the margins of the chamber generated the highly silicic magmas that ultimately pooled at the chamber top.

  11. A statistical approach to the volcanic-plutonic connection

    NASA Astrophysics Data System (ADS)

    Schoene, B.; Keller, C.; Samperton, K. M.; Barboni, M.; Husson, J. M.

    2013-12-01

    The geochemical relationship between volcanic and plutonic rocks - whether the two are geochemically identical, or if the choice between eruption or intrusion is correlated with magma chemistry - represents a major unanswered question in igneous petrology. In one endmember scenario, felsic to intermediate plutons represent the unerupted residue from which crystal-poor eruptible melts are extracted. At the other end of the spectrum, it is argued that a nearly the entire volume of magma is evacuated during eruption, and that the probability of eruption versus intrusion is instead largely a function of magma flux. In the first scenario, parental magmas originating at depth experience substantial fractionation during volcanic melt extraction, leading to complementary volcanic and plutonic reservoirs. In the second endmember scenario, volcanic/plutonic fractionation in the middle to upper crust is negligible, predicting no geochemical difference between volcanic and plutonic rocks. A third endmember scenario that is not exclusive from the other two predicts differences between volcanic and plutonic rocks if geochemical characteristics are correlated with the eventual eruptibility of magma. Deciphering the relative importance of each of these models is important for understanding both the long-term geochemical balance of the crust and mantle due to increased erosion and recycling of volcanic rocks and also for understanding magma transport dynamics. We have compared the geochemistry of ~500,000 volcanic and plutonic rocks from a range of tectonic settings by Monte Carlo bootstrap analysis in order to produce maximally representative average compositions. The results indicate that while volcanic and plutonic rocks in general show remarkably similar major element trends, intermediate to felsic plutonic rocks, for a given silica content, display clear enrichments in Sr and Ba and depletions in Zr, Hf, and HREEs relative to their volcanic equivalents. More subtly

  12. Relationship of voluminous ignimbrites to continental arc plutons: Petrology of Jurassic ignimbrites and contemporaneous plutons in southern California

    USGS Publications Warehouse

    Fohey-Breting, N. K.; Barth, A.P.; Wooden, J.L.; Mazdab, F.K.; Carter, C.A.; Schermer, E.R.

    2010-01-01

    Volcanism was broadly associated in both space and time with Mesozoic plutonism in the Cordillera continental margin arc, but the precise petrogenetic relationships between volcanic rocks and adjacent zoned plutons are not known. Igneous rocks in a tilted crustal section in California include four laterally extensive Jurassic ash flow tuffs from 550 to >1100 m thick underlain at deeper structural levels by Jurassic plutons. Zircon geochronology confirms previous correlations of individual tuffs, suggesting ignimbrites with eruptive volumes up to 800 km3 were deposited both during the apparent Early Jurassic plutonic lull as well as contemporaneous with solidification of regionally widespread Middle and Late Jurassic plutons. The tuffs are weakly to strongly porphyritic (5 to 55% phenocrysts) monotonous intermediate porphyritic dacite to low-silica rhyolite and show strong bulk rock chemical affinity to contemporaneous plutons. Trace element compositions of zircons from the tuffs and contemporaneous plutonic rocks record large and consistent differences in Hf/Zr and REE over similar ranges in Ti abundances, supporting bulk compositional similarities and illuminating similarities and variations in thermal histories despite the effects of hydrothermal alteration. ?? 2009 Elsevier B.V. All rights reserved.

  13. From steep feeders to tabular plutons - Emplacement controls of syntectonic granitoid plutons in the Damara Belt, Namibia

    NASA Astrophysics Data System (ADS)

    Hall, Duncan; Kisters, Alexander

    2016-01-01

    Granitoid plutons in the deeply eroded south Central Zone of the Damara Belt in Namibia commonly show tabular geometries and pronounced stratigraphic controls on their emplacement. Subhorizontal, sheet-like pluton geometries record emplacement during regional subhorizontal shortening, but the intrusion of spatially and temporally closely-related granitoid plutons at different structural levels and in distinct structural settings suggests independent controls on their levels of emplacement. We describe and evaluate the controls on the loci of the dyke-to-sill transition that initiated the emplacement of three syntectonic (560-530 Ma) plutons in the basement-cover stratigraphy of the Erongo region. Intrusive relationships highlight the significance of (1) rigidity anisotropies associated with competent sedimentary packages or pre-existing subhorizontal granite sheets and (2) rheological anisotropies associated with the presence of thick ductile marble horizons. These mechanical anisotropies may lead to the initial deflection of steep feeder conduits as well as subsequent pluton assembly by the repeated underaccretion of later magma batches. The upward displacement of regional isotherms due to the heat advection associated with granite emplacement is likely to have a profound effect on the mechanical stratification of the upper crust and, consequently, on the level at which granitoid pluton emplacement is initiated. In this way, pluton emplacement at progressively shallower crustal depths may have resulted in the unusually high apparent geothermal gradients recorded in the upper crustal levels of the Damara Belt during its later evolution.

  14. Plutonic rocks of Jurassic age in the Alaska-Aleutian Range batholith: chemical variation and polarity.

    USGS Publications Warehouse

    Reed, B.I.; Miesch, A.T.; Lanphere, M.A.

    1983-01-01

    Plutonic rocks of Jurassic age exposed on the Pacific side of this batholith form a compositionally continuous calc-alkaline suite that ranges from hornblende gabbro to quartz monzonite. Tonalite and quartz diorite are the dominant rock types. Trend-surface analysis of 102 samples indicates that the direction of slope of the trend is approximately normal to the Jurassic magmatic arc. K2O and SiO2 increase towards the E-SE and the other oxides towards the W-NW. If the chemical trends reflect the approximate geometry of a palaeo-subduction zone, the polarity of the Jurassic magmatic arc is to the NW, i.e. subduction was directed towards the SE. Thus the palaeo-subduction zone is on the opposite side of the arc from the position that has generally been assumed, indicating that the Jurassic plutonic rocks were not generated in response to classical Andean-type convergent plate margins. The magmatic arc may have been formed in an intra-ocean environment and subsequently has been rafted northwards and accreted to this part of the N Pacific rim during the late Mesozoic. Middle and Upper Jurassic clastics underlying Cook Inlet to the SE and derived from the magmatic arc are classified as back-arc deposits, rather than as an arc-trench gap sequence.-L.C.H.

  15. Gotu Kola (Centella asiatica): Nutritional Properties and Plausible Health Benefits.

    PubMed

    Chandrika, Udumalagala Gamage; Prasad Kumarab, Peramune A A S

    2015-01-01

    Centella asiatica L. (Gotu Kola) is a nutritionally important plant and a valued traditional medicine in South East Asia. In this review, the chemical composition, nutritional values, and health benefits of C. asiatica have been discussed in detail to emphasize its usage as traditional food and medicine. C. asiatica is one of the most commonly used green leafy vegetables (GLVs) in some countries including Sri Lanka due to its high amounts of medicinally important triterpenoids and beneficial carotenoids. It is consumed in the form of GLVs and in the preparation of juice, drink, and other food products. It is also known to contain vitamins B and C, proteins, important minerals, and some other phytonutrients such as flavonoids, volatile oils, tannins, and polyphenol. In vitro and in vivo studies have shown important health benefits like antidiabetic, wound-healing, antimicrobial, memory-enhancing, antioxidant, and neuroprotecting activities. However, detailed scientific approaches on clinical trials regarding health benefits and nutritional values of C. asiatica are limited, hindering the perception of its benefits, mechanisms, and toxicity in order to develop new drug prototypes. In vitro studies have shown that the method of processing C. asiatica has an impact on its nutritional values and health-related beneficial compounds. The composition of its compounds is influenced by different biotic and abiotic factors which need to be studied in detail to provide information to the public in order to maximize the usage of this valuable plant. PMID:26602573

  16. Zircon crystal morphology and internal structures as a tool for constraining magma sources: Examples from northern Portugal Variscan biotite-rich granite plutons

    NASA Astrophysics Data System (ADS)

    Brites Martins, Helena C.; Simões, Pedro P.; Abreu, Joana

    2014-09-01

    In northern Portugal, large volumes of granitoids were emplaced during the last stage (D3) of the Variscan orogeny and display a wide range of petrological signatures. We studied the morphologies and internal structures of zircons from syn-, late- and post-D3 granitoids. The sin-D3 granitoids include the Ucanha-Vilar, Lamego, Felgueiras, Sameiro, and Refoios do Lima plutons, the late- and post-D3 granitoids are represented by the Vieira do Minho and the Vila Pouca de Aguiar plutons, respectively. Typological investigations after Pupin (1980) along with scanning electron microprobe imaging reveal that the external morphology of zircon changes consistently with a decrease in the crystallization temperature. Zircon populations from the Refoios do Lima and the Vieira do Minho granites show gradual changes in the internal morphologies and their typologic evolution trends are consistent with their mainly crustal origin. The Sameiro, Felgueiras, Lamego and Ucanha-Vilar granites have more complex internal and external morphology and typological evolution trends that cross the domain of the calc-alkaline to the aluminous granites compatible with a mixing process. Finally, the morphological types of the Vila Pouca de Aguiar granites are found both in calc-alkaline and sub-alkaline granites and their typological evolutionary trends follow the calc-alkaline/sub-alkaline trend, suggesting crustal sources with some mantle contribution.

  17. Paleocene plutonism and its tectonic implications, North Cascades, Washington

    SciTech Connect

    Miller, R.B. ); Bowring, S.A. ); Hoppe, W.J. )

    1989-09-01

    U-Pb zircon geochronology has identified a northwest-trending belt of Paleocene (68-59 Ma) plutons within the crystalline core of the North Cascades. Most of these plutons show amphibolite facies assemblages and solid-state foiliation. They document extensive Paleogene dynamothermal metamorphism in the core, and combined with other recent studies, demonstrate ongoing metamorphism from mid-Cretaceous to mid-Eocene time. The Paleocene plutons were emplaced during an interval that marked a magmatic lull throughout much of the northern Cordillera. The distribution of latest Cretaceous and Paleocene plutons suggests that magmatism in the North Cascades core records the same eastward retreat that occurred farther north in the Cordillera.

  18. Harper Creek and Cuyamaca Reservoir gneisses, CLMSZ: Late Jurassic plutons of the Peninsular Ranges batholith

    SciTech Connect

    Miller, J.; Girty, G.H.; Girty, M.S. . Dept. of Geological Sciences)

    1993-04-01

    The Cuyamaca Laguna Mountains shear zone (CLMSZ), southern California, has been interpreted to represent east-over-west thrusting resulting from Early Cretaceous arc-continent collision. Near Pine Valley, the western margin of the CLMSZ is underlain by the Harper Creek (HCg) and Cuyamaca Reservoir (CRg) gneisses. U-Pb zircon studies indicate ages of 161 [+-] 17 Ma and 156 [+-] 12 Ma for the Hcg and an age of 158 Ma for the CRg. Geochemically the HCg and CRg are calc-alkaline and peraluminous. Trace element data suggest a magmatic arc setting. Modal and normative mineralogy suggest granodioritic and tonalitic protoliths. Mineral assemblages indicate upper greenschist facies to lower amphibolite grade conditions during deformation. The HCg and CRg were deformed prior to the emplacement of the adjacent 118 [+-] 9 Ma Pine Valley pluton. Structural fabrics described above suggest NE-SW contraction and subvertical extension and are thus compatible with the arc-continent collisional model proposed by earlier workers.

  19. Digital relief 3D model of the Khibiny massive (Kola peninsula)

    NASA Astrophysics Data System (ADS)

    Chesalova, Elena; Asavin, Alex

    2015-04-01

    On the basis of maps of 1: 50,000 and 1: 200,000 3D model Khibiny massif developed. We used software ARC / INFO v10.2 ESRI. This project will be organised to build background for gas pollution monitoring network. We planned to use the model to estimate local heterogeneities in the composition of the atmosphere at the emanation of greenhouse gases in the area, the construction of models of vertical distribution of the content of trace gases in the rock mass. In addition to the project GIS digital elevation model contains layers of geological and tectonic map that allows us to estimate the area of the output of certain petrographic rock groups characterized by different ratios of emitted hydrocarbons (CH4/ H2). The model allows to construct a classification of fault in the array. At first glance, there are two groups of faults - the ancient associated with the formation of the intrusive phases sequence, and the young - due to recent tectonic shifts. Ancient faults form a common semicircular structure of the pluton cause overall asymmetry Khibin heights with the transition to the border area between the Khibiny and Lovoozero. Modern tectonics mainly represented by radial and chord faults which are formed narrow mountain valleys and troughs. It remains an open question as to which system fault (old or young) is more productive to gas emanations? On the one hand the system characterized by a large old depth, on the other hand a young more active faults. Address these issues require further detailed observations. The essential question is to assess the possibility of maintaining a constant concentration gradient of these impurities in the atmosphere due to gas emanations of fracture zones and areas enriched occluded gases. In the simulation of these processes can be used initially set parameters: 1 the flow rate of the gas impurities 2 the value of wind flows in closed and open valley 3 Assessment of thermal diffusion coefficients determined by the temperature gradient

  20. Petrogenesis of the reversely-zoned Turtle pluton, southeastern California

    SciTech Connect

    Allen, C.M.

    1989-01-01

    Few plutons with a reversed geometry of a felsic rim and mafic core have been described in the geologic literature. The Turtle pluton of S.E. California is an intrusion composed of a granitic rim and granodioritic core and common microgranitoid enclaves. Field observations, mineral textures and chemistries, major and trace element geochemistry, and isotopic variability support a petrogenetic model of in situ, concomitant, magma mixing and fractional crystallization of rhyolitic magma progressively mixed with an increasing volume of andesitic magma, all without chemical contribution from entrained basaltic enclaves. Hornblende geobarometry indicates the Turtle pluton crystallized at about 3.5 kb. A crystallization sequence of biotite before hornblende (and lack of pyroxenes) suggests the initial granitic magma contained less than 4 wt% H{sub 2}O at temperatures less than 780C. U-Pb, Pb-Pb, Rb-Sr and oxygen isotope studies indicate the terrane intruded by the Turtle pluton is 1.8 Ga, that the Turtle pluton crystallized at 130 Ma, that the Target Granite and garnet aplites are about 100 Ma, and that these intrusions were derived from different sources. Models based on isotopic data suggest the rhyolitic end member magma of the Turtle pluton was derived from mafic igneous rocks, and was not derived from sampled Proterozoic country rocks. Similarity of common Sr and Pb isotopic ratios of these rocks to other Mesozoic intrusions in the Colorado River Region suggest the Turtle pluton and Target Granite have affinities like rocks to the east, including the Whipple Mountains and plutons of western Arizona. P-T-t history of the southern Turtle Mountains implies uplift well into the upper crust by Late Cretaceous time so that the heating and deformation events of the Late Cretaceous and Tertiary observed in flanking ranges did not affect the study area.

  1. Geophysical modeling and structure of Ushuaia Pluton, Fuegian Andes, Argentina

    NASA Astrophysics Data System (ADS)

    Peroni, Javier Ignacio; Tassone, Alejandro Alberto; Menichetti, Marco; Cerredo, María Elena

    2009-10-01

    Within the area of Ushuaia Bay (Tierra del Fuego, southernmost South America) the deformed Lower Cretaceous sedimentary rocks of Yahgán Formation host the Ushuaia Pluton. The intrusive body is oval in map view; it is compositionally varied with rocks ranging from the ultrabasic to the mesosiliceous realm. The emplacement time is constrained within the Albian-Cenomanian span by new amphibole K/Ar data. Meso- and microstructures of Ushuaia Pluton and its host indicate a synkinematic emplacement with a dominant extensional component. A set of transcurrent and normal faults related to the sinistral strike-slip Beagle Channel Fault System affects the pluton and its host. On the basis of aeromagnetic data combined with field information, a new model is presented for the Ushuaia Pluton. Modeling results fit well with a laccolithic body with an estimated volume of around 111 km 3. The model pluton cross-section displays a central zone with an average thickness of 2000 m which progressively thins toward the margins (˜ 500 m) and a southern root which reaches 5000 m deep. The combined structural and geophysical model supports a transtensive scenario for the Ushuaia Pluton emplacement at Early-Late Cretaceous boundary.

  2. Petrogenesis of the Dengzhazi A-type pluton from the Taihang-Yanshan Mesozoic orogenic belts, North China Craton

    NASA Astrophysics Data System (ADS)

    Xiaolu, Niu; Bin, Chen; Xu, Ma

    2011-05-01

    The voluminous Mesozoic monzonitic to monzogranitic rocks in the north China craton (NCC) mostly show high-K calc-alkaline and I-type granitoids features. The Dengzhazi granitic pluton, however, shows features typical of A-type granites. The A-type pluton was emplaced in the Taihang-Yanshan orogenic belts of the northern margin of the NCC, with zircon U-Pb ages of around 140 Ma. The Dengzhazi A-type granites are characterized by high SiO 2 (70.2-77.7 wt.%), K 2O + Na 2O, Zr, Nb, Ga, Zn, and Y contents as well as high Ga/Al ratios, and extremely low CaO, Ba, Sr. In addition, they show high zircon saturation temperatures (870-950 °C), low water and low oxygen fugacity. All these features are consistent with the A-type affinity of the pluton. In situ Hf isotopic analyses for the dated zircons show relatively small range of ɛHf( t) (-13 to -17). They also have homogeneous initial Nd isotopic compositions with ɛNd( t) ranging from -15.1 to -16.3. The Hf and Nd isotopic data suggest that the Dengzhazi A-type granites originated from a homogeneous crustal source, probably the Archean mafic-intermediate granulites. Taking into account the high temperatures, the low H 2O and fO 2 of the magma system, we believe that partial melting of the granulites should have been triggered by underplating of mantle-derived magmas at the base of the mafic lower crust in an extensional regime. The Dengzhazi A-type granite is the oldest pluton of the Taihang-Yanshan Mesozoic magma belts, signifying the commencement of extensive underplating of mafic magmas, and thus of lithospheric thinning in the northern NCC.

  3. Genesis of peat-bog soils in the northern taiga spruce forests of the Kola Peninsula

    SciTech Connect

    Nikonov, V.V.

    1981-01-01

    The characteristics of soil formation processes in the Peat-Bog soils of waterlogged spruce phytocenoses on the Kola Peninsula are investigated. It is found that the ash composition of the peat layer is determined primarily by the composition of the buried plant residues. The effect of the chemical composition of water feeding the peat bogs is determined. (Refs. 7).

  4. ALP (Alkaline Phosphatase) Test

    MedlinePlus

    ... known as: ALK PHOS; Alkp Formal name: Alkaline Phosphatase Related tests: AST ; ALT ; GGT ; Bilirubin ; Liver Panel ; Bone Markers ; Alkaline Phosphatase Isoenzymes; Bone Specific ALP All content on Lab ...

  5. Anatomy of the Cretaceous Hobenzan pluton, SW Japan: Internal structure of a small zoned pluton, and its genesis

    NASA Astrophysics Data System (ADS)

    Imaoka, Teruyoshi; Nakashima, Kazuo; Kamei, Atsushi; Hayasaka, Yasutaka; Ogita, Yasuo; Ikawa, Toshiyuki; Itaya, Tetsumaru; Takahashi, Yoshio; Kagami, Hiroo

    2014-11-01

    Field, petrographic, geochemical, and K-Ar and U-Pb age data were used to elucidate the internal structure of the Cretaceous Hobenzan pluton, SW Japan, and the processes which generated that structure. The pluton is elongated E-W with dimensions of about 6.5 × 2.0 km (13 km2), and was emplaced at ~ 95 Ma as a pluton in accretionary complexes. The pluton contains an early tonalite, but most of the body consists of later granitoids that show a continuous differentiation series from biotite-hornblende granodiorite (GD) to hornblende-biotite granite (HBG) and biotite granite (BG). The contacts between the GD and HBG are gradational. The pluton provides an exceptional cross-sectional view of a simple cooling magma body. The GD shows no vertical variations in modal and chemical compositions, whereas the HBG displays differentiation from the lowermost exposure to the top of the pluton. Initial Sr isotope ratios (SrI) in the HBG increase from the lower part to the top of the pluton. The granitoids show continuous compositional variations from 65 to 79 wt.% SiO2 (anhydrous basis), and magmatic differentiation was dominantly controlled by crystal fractionation of hornblende and plagioclase. Field, elemental and Sr-Nd isotope data are consistent with limited operation of assimilation with pelitic rocks and fractional crystallization (AFC), in which assimilation increased with higher degrees of differentiation. The Hobenzan pluton retains a history of granitoid magma evolution in a subvolcanic magma reservoir. The GD formed as a rigid sponge, and melt fraction increases inwards from the walls, forming the HBG mush by fractional crystallization, coupled with small degrees of assimilation of adjacent schists. A more evolved and enriched low-density melt segregated from the mushy cumulate of the HBG by incomplete crystal-melt separation, and moved upwards with the assistance of gas-driven filter pressing, as indicated by the presence of miarolitic cavities, thus forming the BG

  6. Survey of lunar plutonic and granulitic lithic fragments

    NASA Technical Reports Server (NTRS)

    Bickel, C. E.; Warner, J. L.

    1978-01-01

    A catalog of lunar plutonic rocks and granulitic impactites belonging to the ANT suite has been compiled. The coarser-grained, plutonic rocks in the compilation are probably pristine; they belong to two groups, Mg-rich plutonic rocks and anorthosites, with a preponderance of the latter type. The granulitic impactites, however, have bulk and mineral compositions that fall between the two groups defined by the pristine nonmare samples of Warren and Wasson (1977). Thus the granulitic impactites may have originated by metamorphism of mixed impactites in early breccia sheets. The catalog, representative of the lunar crust before the end of heavy bombardment, suggests a crust with over 78 vol. % plagioclase and about equal proportions of material with noritic and troctolitic affinity.

  7. An AMS study of the Takidani pluton (Japan)

    NASA Astrophysics Data System (ADS)

    Hartung, Eva; Caricchi, Luca; Floess, David; Wallis, Simon; Harayama, Satoru

    2016-04-01

    Large plutonic bodies are typically constructed incrementally often by under-accretion of distinct successive magma pulses. Petrography and geochemistry of the Takidani Pluton (1.54 Ma ± 0.23 Ma) in the Northern Japanese Alps show that the chemical and textural variability observed at the roof of this intrusion is best explained by the segregation of residual melt from a crystallising magma body. We carried out a magnetic susceptibility survey (bulk susceptibility and anisotropy of magnetic susceptibility) to identify the structures associated with the emplacement and extraction of residual melts from a magmatic mush. Additionally, we determined shape preferred orientations (SPO) of amphibole at several locations within the Takidani pluton. From bottom to top of the intrusion, the bulk susceptibility is about constant in the main granodioritic part, decreases roofwards within the porphyritic unit, before increasing again within the marginal granodiorite close to the contact with the overlaying Hotaka Andesite. Such variability mimics the major and trace elements compositional variability measured in the whole rock samples. Magnetic foliations are observed at the western tectonic contact of the pluton potentially indicating overprint, while most other magnetic fabrics across the pluton are characterised by triaxial ellipsoids of magnetic susceptibility or magnetic lineations. Our preliminary data and the lack of internal contacts indicate that Takidani Pluton was likely emplaced as a series of successive magma pulses finally merging to produce a large connected magma body. While amphibole foliations may likely be the results of super-solidus tectonic overprint, anisotropy of magnetic susceptibility data may be related to post-emplacement melt segregation.

  8. The Plutón Diorítico Moat: Mildly alkaline monzonitic magmatism in the Fuegian Andes of Argentina

    NASA Astrophysics Data System (ADS)

    González Guillot, M.; Escayola, M.; Acevedo, R.; Pimentel, M.; Seraphim, G.; Proenza, J.; Schalamuk, I.

    2009-12-01

    The Plutón Diorítico Moat (Moat Dioritic Pluton, PDM) is the largest of several isolated Cretaceous plutons exposed in the Fuegian Andes of Argentina. It is made of a large variety of rock types ranging from ultramafic bodies (pyroxenites and hornblendites) to syenites. The petrological diversity is thought to have been originated by fractional crystallization of a mantle-derived magma combined with minor assimilation of continental crust (AFC). Its geochemical characteristics indicate a mildly-alkaline monzonitic affinity, contrasting with the typical calc-alkaline plutons of the Southern Patagonian Batholith (PB) to the south, in the Chilean archipelago. The PDM original magma is arc-related and its crystallization, as indicated by the Rb-Sr mineral isochron age of 115 ± 3 Ma, is coeval with some plutons of the PB. Therefore a similar tectonic regime is assumed for the emplacement of these plutonic bodies, both south and north of the Beagle channel. Differences in magma sources and degree of partial melting are inferred to account for the contrasting lithological and geochemical characteristics of the PB and PDM. The data suggest that the original magmas of the PDM were generated at greater depths in the mantle, by a smaller degree of partial melting, compared with the PB. The Barros Arana basalts, exposed to the north in Chile, forming a back-arc volcanic complex, display the same mildly-alkaline shoshonitic affinity, and are considered in this study as the volcanic equivalents of the PDM. All the plutons in the Argentinean Fuegian Andes display similar lithological and geochemical characteristics and are, therefore, grouped in this work under the name of Magmatismo Potásico Fueguino ( Fuegian Potassic Magmatism).

  9. Amino acid composition of two masticatory nuts (Cola acuminata and Garcinia kola) and a snack nut (Anacardium occidentale).

    PubMed

    Adeyeye, E I; Asaolu, S S; Aluko, A O

    2007-06-01

    The amino acid compositions of Cola acuminata, Garcinia kola and Anacardium occidentale were evaluated by ion-exchange chromatography. Glutamic acid was the most concentrated acid in the samples. In all the amino acids determined, A. occidentale had the most concentrated acid on a pairwise basis. The total amino acids were 356.24 mg/g protein, 112.90 mg/g protein and 659.17 mg/g protein for C. acuminata, G. kola and A. occidentale, respectively. The percentage total essential amino acids were 38.39% (C. acuminata), 47.05% (G. kola) and 51.04% (A. occidentale). Also the percentage total acidic amino acids were 38.16% (C. acuminata), 30.61% (G. kola) and 30.35% (A. occidentale). The calculated isoelectric points were 2.0 (C. acuminata), 0.7 (G. kola) and 3.9 (A. occidentale), showing they can all be precipitated at acidic pH. While threonine was the limiting amino acid in A. occidentale, it was valine in both C. acuminata and G. kola. The percentage cystine (Cys) levels in the total sulphur amino acid were 44.27% (C. acuminata), 37.75% (G. kola) and 50.51% (A. occidentale). The aim of this work was to compare the amino acid profile of the samples. It is recommended that C. acuminata and G. kola consumption be avoided by ulcer patients because of their high levels of acidic amino acids. A. occidentale amino acid scores ranged from 42% to 127%, suggesting that it could be used to enhance the protein quality of cereals through food complementation. PMID:17566886

  10. Plutonic processes recorded in Iceland's volcanic rocks

    NASA Astrophysics Data System (ADS)

    Maclennan, J.

    2013-12-01

    It has long been understood that the compositions of volcanic rocks from basaltic provinces contain information about magmatic differentiation processes. Whole-rock or pillow-rim glass compositions have previously been sucessfully modelled using the single liquid line of descent (LLD) approach. While the expected cumulate products from the crystallisation and differentiation that drives these LLDs can be predicted from the models, this approach provides little information about the physical nature of the chambers that control basaltic evolution. Development in microanalysis now allows for new types of observations to be acquired that can be used to probe the physics of basaltic chambers. Here, we explore three distinct types of observations from the products of young Icelandic volcanic eruptions which can be used to understand plutonic processes in basaltic systems. Ultimately, these observations can be tied to simple physical models of magma chambers, with the aim of quantifying vigour of convection in magma chambers, the related timescales of evolution and the heights of liquid and mush layers in active chambers. The first observation is based on the relationship between the composition of melt inclusions and the forsterite content of their olivine hosts. Certain trace element ratios, such as La/Yb, are effectively passive tracers of mixing of diverse mantle melts under Iceland. The forsterite content of the host olivine tracks the cooling and differentiation of these mixing liquids. The observations indicate the cooling and mixing is concurrent and is likely to be coupled by convection in liquid layers of magma chambers. Relative rates of mixing and cooling can be quantified from these observations and linked to the vigour of convection in the liquid layer of the chamber. The absolute rate of cooling of these chambers is also linked to the Rayleigh number in this layer, and this value can be constrained by geochemical and geological observations from Iceland

  11. Infrasound research at Kola Regional Seismological Centre, Russia

    NASA Astrophysics Data System (ADS)

    Asming, Vladimir; Kremenetskaya, Elena

    2013-04-01

    A small-aperture infrasound array has been installed in Kola Peninsula, Russia 17 km far from the town of Apatity in the year 2000. It comprises 3 Chaparral V microbarographs placed closely to the APA seismic array sensors and equipped with pipe wind reducing filters. The data are digitized at the array site and transmitted in real time to a processing center in Apatity. To search for infrasound events (arrivals of coherent signals) a beamforming-style detector has been developed. Now it works in near real time. We analyzed the detecting statistics for different frequency bands. Most man-made events are detected in 1-5 Hz band, microbaromes are typically detected in 0.2-1 Hz band. In lower frequencies we record mostly a wind noise. A data base of samples of infrasound signals of different natures has been collected. It contains recordings of microbaromes, industrial and military explosions, airplane shock waves, infrasound of airplanes, thunders, rocket launches and reentries, bolides etc. The most distant signals we have detected are associated with Kursk Magnetic Anomaly explosions (1700 km far from Apatity). We implemented an algorithm for association of infrasound signals and preliminary location of infrasound events by several arrays. It was tested with Apatity data together with data of Sweden - Finnish infrasound network operated by the Institute of Space Physics in Umea (Sweden). By agreement with NORSAR we have a real-time access to the data of Norwegian experimental infrasound installation situated in Karasjok (North Norway). Currently our detection and location programs work both with Apatity and Norwegian data. The results are available in Internet. Finnish militaries routinely destroy out-of-date weapon in autumns at the same compact site in North Finland. This is a great source of repeating infrasound signals of the same magnitude and origin. We recorded several hundreds of such explosions. The signals have been used for testing our location routines

  12. Geochronology of the Archaean Kolmozero-Voron'ya Greenstone Belt: U-Pb dating of zircon, titanite, tourmaline and tantalite (Kola Region, North-Eastern BAltic Shield)

    NASA Astrophysics Data System (ADS)

    Kudryashov, N.; Gavrilenko, B.; Apanasevich, E.

    2003-04-01

    The Archaean Kolmozero-Voron’ya greenstone belt is one of the most ancient geological structures of the Kola Peninsula. It is located between Upper Archaean terrains: Murmansk, Central Kola and Keivy. Within the Kolmozero-Voron'ya greenstone belt there are rare metal (Li, Cs with accessory Nb, Ta, and Be), Cu, Mo, and Au deposits. All rocks were metamorphosed under amphibolite facies conditions and intruded by granodiorites, plagiomicrocline and tourmaline granites and pegmatite veins. Four suites are distinguished within the belt: lower terrigenous formation, komatiite-tholeite, basalt-andesite-dacite and upper terrigenous formation. The U-Pb age of 2925±6 Ma on magmatic zircon was obtained for leucogabbro of differentiated gabbro-anorthosite massif Patchemvarak, situated at the boundary between volcanic-sedimentary units and granitoids of the Murmansk block. This age is the oldest for gabbro-anorthosites of the Kola Peninsula. Sm-Nd age of komatiites is ca. 2.87 Ga (Vrevsky, 1996). U-Pb age of zircon from biotite schist, which belongs to acid volcanites is 2865+/-5 Ma. Quartz porphyries, which are considered to be an intrusive vein analogous of acid volcanites has an age of 2828+/-8 Ma, that marks the final stage of the belt development. Dating of titanite from ovoid plagioamphibolites yielded an U-Pb age of 2595+/-20 Ma that probably is connected with the closure of the U-Pb isotopic titanite system during the regional metamorphism. The Porosozero granodioritic complex with an age of 2733+/-6 Ma is located between granites of the Murmansk domain, migmatites and gneisses of the Central Kola terrain and the Keivy alkaline granites. Tourmaline granites are found all over the Kolmozero-Voron’ya belt occurring among volcanogenic-sedimentary rocks of the belt. Their Pb-Pb age of 2520+/-70 Ma appears to denote the tourmaline crystallization at a post-magmatic stage of the complex formation. U-Pb zircon age from rare metal pegmatites is 1.9-1.8 Ga. Zircons from

  13. Anorthosites and alkaline rocks from the deep crust of peninsular India

    NASA Technical Reports Server (NTRS)

    Leelanandam, C.; Ratnakar, J.; Reddy, M. Narsimha

    1988-01-01

    The anorthosite and alkaline rock localities in the Precambrian Shield of Peninsular India were reviewed. There are approximately 50 localities of such rocks, generally restricted to the Eastern Ghats mobile belt. The alkaline plutons are typically confined to the margin of the Eastern Ghats. The anorthosites are all greater than 500 sq km, but many exhibit similarities to one another. It was suggested that the anorthosites are associated with cryptic sutures, and are thought to have originated as a result of ponding of basaltic magmas. An analogy was drawn between the Eastern Ghats belt and the Grenville Province of the Canadian Shield.

  14. The Neutron Tomography Studies of the Rocks from the Kola Superdeep Borehole

    NASA Astrophysics Data System (ADS)

    Kichanov, S. E.; Kozlenko, D. P.; Ivankina, T. I.; Rutkauskas, A. V.; Lukin, E. V.; Savenko, B. N.

    The volume morphology of a gneiss sample K-8802 recovered from the deep of 8802 m of the Kola Superdeep Borehole and its surface homologue sample PL-36 have been studied by means of neutron radiography and tomography methods. The volumes and size distributions of a biotite-muscovite grains as well as grains orientation distribution have been obtained from experimental data. It was found that the average volumes of the biotite-muscovite grains in surface homologue sample is noticeably larger than the average volume of grains in the deep-seated gneiss sample K-8802. This drastically differences in grains volumes can be explained by the recrystallization processes in deep of the Kola Superdeep Borehole at high temperatures and high pressures.

  15. Apros-based Kola 1 nuclear power plant compact training simulator

    SciTech Connect

    Porkholm, K.; Kontio, H.; Nurmilaukas, P.

    1996-11-01

    Imatran Voima Oy`s subsidiary IVO International Ltd (IVO IN) and the Technical Research Centre of Finland (VTT) in co-operation with Kola staff supplies the Kola Nuclear Power Plant in the Murmansk region of Russia with a Compact Training Simulator. The simulator will be used for the training of the plant personnel in managing the plant disturbance and accident situations. By means of the simulator is is also possible to test how the planned plant modifications will affect the plant operation. The simulator delivery is financed by the Finnish Ministry of Trade and Industry and the Ministry of Foreign Affairs. The delivery is part of the aid program directed to Russia for the improvement of the nuclear power plant safety.

  16. Electromagnetic sounding of the Kola Peninsula with a powerful extremely low frequency source

    NASA Astrophysics Data System (ADS)

    Velikhov, E. P.; Grigoriev, V. F.; Zhdanov, M. S.; Korotayev, S. M.; Kruglyakov, M. S.; Orekhova, D. A.; Popova, I. V.; Tereschenko, E. D.; Schors, Y. G.

    2011-05-01

    Experiment on electromagnetic sounding of the Kola Peninsula using unique mobile measuring complex of the low-frequency sounding was conducted, allowing to investigate a geoelectric section with a depth of several kilometers on distances up to 100 km from the stationary transmitting aerial. Excess on the order of amplitudes of the vertical component above the horizontal at all frequencies of sounding was registered in a number of points of measurements. This feature managed to be explained quantitatively by circulation of current on regional faults with the closure of current through the sea—before unknown galvanic coastal effect. Interpretation of the results of modeling and neural network solving of inverse problem essentially specifies the fault tectonics of the central part of the Kola Peninsula. Anomaly remote from the observation profile was found out—local pinch of a crustal conductive layer consisting of graphitized rocks and associated with the zone of overthrust.

  17. Geochemistry and zircon U-Pb-Hf isotopes of the granitoids of Baolidao and Halatu plutons in Sonidzuoqi area, Inner Mongolia: Implications for petrogenesis and geodynamic setting

    NASA Astrophysics Data System (ADS)

    Hu, Chuansheng; Li, Wenbo; Xu, Cheng; Zhong, Richen; Zhu, Feng

    2015-01-01

    The Baolidao and Halatu plutons are located in the Northern Orogenic Belt (NOB) in Sonidzuoqi area of Inner Mongolia, which has an important significance for the tectonic evolution of Xing-Meng Orogenic Belt (XMOB). The two plutons have been intensively studied but the conclusions are still controversial. Combined with the previous study, this paper gives new geological data about the two correlative plutons for gaining a better understanding of their petrogenesis and the geodynamic setting. The Baolidao granitoids contain two different series, calc-alkaline series mainly formed in the Ordovician and high K calc-alkaline series mainly formed in the Carboniferous. The Halatu granites are formed in the Triassic and belong to high-K calc-alkaline series. This study got the zircon U-Pb ages of 316-322 Ma for the Baolidao granitoids and 233 ± 2 Ma for the Halatu syenogranites, respectively. In the tectonic discrimination diagrams, they mainly fall into the area of post-orogenic granites (POG). Hf isotopic analyses for the Baolidao granitoids (Sample BLD-1 and 3) shows εHf (t) = 3.0-14.0, with two-stage Hf model age (TDM2) of 436-1138 Ma. The Halatu syenogranite (Sample HLT-1) also shows a depleted εHf (t) = 3.8-8.2, with TDM2 of 741-1024 Ma, suggesting the major involvement of juvenile crustal components. The various εHf values of the Carboniferous Baolidao and Triassic Halatu granitoids indicates a hybrid magma source of juvenile material with old crustal component, and the εHf (t) values decrease from the Carboniferous to Triassic, suggesting the increasing proportion of old continental material during this period. Combined with the regional geology, the Carboniferous Baolidao granitoids are possibly not arc rocks, but originated from the post-collisional setting. The Triassic Halatu granites were formed in the subsequently extensional environment.

  18. Geochemistry and geochronology of the volcano-plutonic rocks associated with the Glojeh epithermal gold mineralization, NW Iran

    NASA Astrophysics Data System (ADS)

    Siani, Majid Ghasemi; Mehrabi, Behzad; Azizi, Hossein; Wilkinson, Camilla Maya; Ganerød, Morgan

    2015-08-01

    Eocene to Oligocene volcano-plutonic rocks are widespread throughout NW Iran. The Tarom-Hashtjin metallogenic province is one of the most promising epithermal-porphyry ore mineralized districts in NW Iran. The Glojeh gold deposit, located in the center of this province, is a typical high to intermediate sulfidation epithermal system, spatially and temporally associated with a granite intrusion and associated high-K calc-alkaline to shoshonitic volcano-plutonic rocks. The intrusive complexes of the Glojeh district are characterized by: SiO2 contents of 60.9 to 70.7 wt.%, K2O+Na2O of 7.60 to 8.92 wt.%, and K2O/Na2O ratios of 0.9 to 1.8. They are enriched in light rare earth elements (LREEs), and large ion lithophile elements (LILEs), depleted in high field strength elements (HFSEs), and have weak negative Eu anomalies (Eu/Eu*= 0.5 to 0.9). 40Ar/39Ar geochronology applied to biotite and feldspar, separated from two intrusives (Goljin and Varmarziar), and two feldspar aliquots separated from hydrothermal veins at North Glojeh and South Glojeh, was carried out to constrain magmatic and hydrothermal events. Plagioclase (± sericite), from North Glojeh and South Glojeh produced ages (42.20±0.34 Ma, and 42.56±1.47 Ma respectively) that overlap with the age of the Goljin intrusion (41.87±1.58 Ma). Geochemical data for the volcano-plutonic rocks in the Glojeh district, that have87Sr/86Sr isotopic compositions that range from 0.706344 to 0.708331, suggest an origin involving partial melting of a depleted mantle source during Neo-Tethyan subduction.

  19. In Vitro and In Vivo Biochemical Evaluations of the Methanolic Leaf Extract of Garcinia kola.

    PubMed

    Badmus, Jelili A; Adedosu, Olaniyi T; Adeleke, Emmanuel G; Akinboro, Kehinde H; Odeyemi, Bayonle I; Ayoola, Bolanle I; Hiss, Donavon C

    2014-01-01

    Garcinia kola Heckel (Guttiferae) leaves have received limited scientific attention despite their traditionally acclaimed medicinal properties. The scavenging ability of the methanolic leaf extract (MLE) of G. kola was assayed for hydroxyl radical (OH(•)), superoxide anion (O2 (-)), 1,1-diphenyl-2-picrylhydrazyl (DPPH), azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS(•+)), and lipid peroxidation (LP) activity in egg yolk, rat liver, and brain homogenates. Total phenolic and flavonoid contents of the extract were also evaluated. Group I animals were given oral doses of water, whereas Group II and Group III animals received 100 and 200 mg/kg body weight (bw) MLE, respectively, for 14 days. Plasma glucose, magnesium, γ-glutamyltransferase (GGT/γGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, and urea were evaluated. Hepatic reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), LP, and liver histopathological appearance were also assessed. The extract scavenged OH(•), O2 (-), DPPH, and ABTS(•+) and inhibited LP in egg yolk, rat liver, and brain homogenates. Furthermore, oral administration of the extract showed no adverse effects on hepatic and renal function tests. Increased hepatic GSH and nonsignificant changes in LP, GPx and SOD activities, and liver histology were observed. These results suggest that G. kola leaves have antioxidant activities which may have application in traditional medicine. PMID:27355075

  20. In Vitro and In Vivo Biochemical Evaluations of the Methanolic Leaf Extract of Garcinia kola

    PubMed Central

    Badmus, Jelili A.; Adedosu, Olaniyi T.; Adeleke, Emmanuel G.; Akinboro, Kehinde H.; Odeyemi, Bayonle I.; Ayoola, Bolanle I.; Hiss, Donavon C.

    2014-01-01

    Garcinia kola Heckel (Guttiferae) leaves have received limited scientific attention despite their traditionally acclaimed medicinal properties. The scavenging ability of the methanolic leaf extract (MLE) of G. kola was assayed for hydroxyl radical (OH•), superoxide anion (O2−), 1,1-diphenyl-2-picrylhydrazyl (DPPH), azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS•+), and lipid peroxidation (LP) activity in egg yolk, rat liver, and brain homogenates. Total phenolic and flavonoid contents of the extract were also evaluated. Group I animals were given oral doses of water, whereas Group II and Group III animals received 100 and 200 mg/kg body weight (bw) MLE, respectively, for 14 days. Plasma glucose, magnesium, γ-glutamyltransferase (GGT/γGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, and urea were evaluated. Hepatic reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), LP, and liver histopathological appearance were also assessed. The extract scavenged OH•, O2−, DPPH, and ABTS•+ and inhibited LP in egg yolk, rat liver, and brain homogenates. Furthermore, oral administration of the extract showed no adverse effects on hepatic and renal function tests. Increased hepatic GSH and nonsignificant changes in LP, GPx and SOD activities, and liver histology were observed. These results suggest that G. kola leaves have antioxidant activities which may have application in traditional medicine.

  1. Miscellaneous investigations series: Bedrock geologic map of the Lone Mountain pluton area, Esmeralda County, Nevada

    SciTech Connect

    Maldonado, F.

    1984-12-31

    The joint attitudes were measured in the field and plotted on aerial photos at a scale of 1:24,000. The pluton is intensely jointed, primarily as a result of cooling and movement of the magma within a northwest-trending stress field. Foliation, in general, is poorly developed, and quality varies from area to area, but it is best developed close to the contacts with the metasedimentary rocks. A prominent northwest foliation direction was observed that parallels the northwest elongation of the exposed pluton. Faults in the pluton are difficult to identify because of the homogeneity of the rock. Several faults were mapped in the northern part of the area where they have a northeast trend and intersect the northwest-trending lamprophyre dikes with little apparent displacement. A major fault that bounds the northern part of the pluton is downthrown to the north and strikes northeast. This fault offsets the alluvium, the metasedimentary rocks, and the pluton and forms fault scraps as high as 10 m. Aeromagnetic data (US Geological Survey, 1979) suggest the following: (1) the local magnetic highs in the central part of the Lone Mountain pluton are probably related to topographic highs (peaks) where the flight lines are closer to the pluton; (2) a magnetic low in the northeastern part of Lone Mountain coincides with the pluton-country rock contact, which may be very steep; (3) the contours for the southwestern part of the mapped area indicate that the pluton-country rock contact is not as steep as that in the northeastern part and that the pluton probably coalesces at depth with the Weepah pluton, a pluton exposed south of the mapped area; and (4) the contours for the area of the Lone Mountain pluton express a northwest-trending gradient that parallels the northwest elongation of the Lone Mountain pluton and the northwest-trending stress field. 10 refs.

  2. Stoping & Screen Formation In The Wooley Creek Batholith And Andalshatten Pluton: Complex Pluton - Host Rock Interactions During Magma Emplacement

    NASA Astrophysics Data System (ADS)

    Yoshinobu, A. S.; Hargrove, B.

    2010-12-01

    The presence of xenoliths in plutons is often assumed to either be due to stoping or the formation of screens. Stoped blocks are defined as having undergone significant translation, rotation, and/or internal deformation while incorporated in the magma, while screens are considered to be relatively in situ. However, there remains much controversy as to 1) the relative spatial distribution of xenoliths/screens in plutons; 2) the degree to which xenoliths/screens may or may not have moved within the magma; 3) the extent of melting and assimilation xenoliths undergo; and 4) the mechanism by which xenoliths and screens are incorporated into plutons. We describe field and structural relations from the tilted Wooley Creek batholith (WCb) and the mid-crustal Andalshatten pluton (AHp). Both intrusions preserve xenoliths/screens of a variety of lithologies that correspond to the host rocks. The WCb is a 158-155 MA tilted intrusion emplaced into a series of accreted terranes in the Marble Mountains Wilderness, Klamath Mountains, CA. Previous work has demonstrated that the WCb is complexly zoned, and can be divided into three distinct structural units: a structurally deep unit ranging from gabbro to tonalite, a structurally shallow unit ranging from diorite to granite, and an intermediate unit of intensely deformed quartz diorite and tonalite. Numerous xenoliths of metric to centimetric scale occur in this intermediate zone, as well as in proximity to the pluton roof as exposed along the southern contact. While many of these xenoliths have internal structures that are discordant to those found in the host rock, others seem to maintain concordance with the regional bedding, and are identified as screens. In nearly all cases, xenoliths appear partially migmatitic, and veining of the host magma into them is common. The 442 Ma AHp is a large, predominantly granodioritic pluton in the Bindal Batholith. It intrudes four lithologically distinct and structurally complex nappes of the

  3. Reconstruction of early Holocene paleoclimate and environment in the SW Kola region, Russian Arctic

    NASA Astrophysics Data System (ADS)

    Grekov, Ivan; Kolka, Vasiliy; Syrykh, Liudmila; Nazarova, Larisa

    2016-04-01

    In the current period of the global climate change it becomes necessary to have a clear understanding of not only the changes taking place in the components of the natural environment, but also to understand development of all interactions between those components. Quaternary terrigenic sediments and lakes of the Kola Peninsula store information about the development of the region in the Late Glacial and Holocene: movements of the glacier, neotectonic activity, post-glacial rebound, formation and development of natural environments after deglaciation. Multi-proxy study of landscapes evolution of the Kola Peninsula in the Late Quaternary will help to establish a detailed reconstruction of climatic and environmental changes of this poor studied sector of the Arctic. Quaternary history on the Kola Peninsula is represented mainly by Late Pleistocene and Holocene sediments covering the Baltic Shield (Lavrova, 1960; Evzerov, 2015). Several palaeolimnological investigations in the Baltic Shield area have been performed earlier (Donner et al., 1977; Anundsen, 1985; Berglund, 2004). Studies of the southern coast of the Kola Peninsula have shown that marine transgression took place in the Late Pleistocene that was then replaced by a regression with variable speed. The slowdown of the uplift of the area took place between 8800 - 6800 BP (cal. years) and corresponded to the time of the Tapes transgression of the Arctic Ocean (Evzerov et al. 2010; Kolka, et al., 2013). Palaeoclimatic studies based on micro-paleontological analyzes indicate uneven development of the Kola Peninsula landscapes in the Late Glacial and Early Holocene. The northern coast of the Peninsula became free of ice first. In this area tundra-steppe vegetation was established for a short time and was later replaced by tundra (Snyder et al, 2000). Southern part of the Kola Peninsula was dependent on the conditions of deglaciation of the White Sea basin and cleared of ice much later (Evzerov et al., 2010; Kolka

  4. Alkaline "Permanent" Paper.

    ERIC Educational Resources Information Center

    Pacey, Antony

    1991-01-01

    Discussion of paper manufacturing processes and their effects on library materials focuses on the promotion of alkaline "permanent" paper, with less acid, by Canadian library preservation specialists. Standards for paper acidity are explained; advantages of alkaline paper are described, including decreased manufacturing costs; and recyclability is…

  5. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  6. Magma flow recorded by magmatic and magnetic fabrics in a shallow granitic pluton: La Gloria Pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Payacán, I. J.; Gutiérrez, F. J.; Gelman, S. E.; Bachmann, O.; Parada, M. A.

    2013-12-01

    To better understand the dynamics of a small, shallow, silicic magma reservoir, magmatic and magnetic (AMS) fabrics are compared in samples obtained from La Gloria Pluton (LGP), a 10 Ma granitic intrusion located in southern Andes. The magnetic fabric of LGP, mainly given by magnetite, is characterized by oblate shapes. Magnetic lineations have a NW trend with subhorizontal dip, following the main pluton elongation, while magnetic foliation planes have dips varying gradually from vertical at the walls to subhorizontal toward the center and the roof of the pluton. On the basis of numerical simulations, magnetic fabric was interpreted to represent the shear record induced by magmatic convection along solidification fronts as the reservoir reached its rheological locking point. Magmatic fabric (mineral orientation) was determined on 12 samples along the pluton. Three mutually orthogonal thin sections were produced for each sample, perpendicular to the AMS tensor axes. Size and orientation of individual crystals were obtained by image analysis. A 2-D tensor for two mineral groups (plagioclase and amphibole+biotitie) was defined in each mineral plane projecting the crystal lengths on the main crystal orientation (given by Bingham statistics). A 3-D magmatic fabric tensor was obtained. In order to compare the magmatic and magnetic fabrics, magmatic anisotropy parameters were defined similar to the AMS tensors. Magmatic fabric and anisotropy parameter values vary depending on the location inside the pluton: (1) Samples located at the borders exhibit vertical foliations and lineations with a NW trend, similar to the magnetic fabric tensors and higher anisotropy values for plagioclase than amphibole+biotite,; (2) samples located at the center of the LGP commonly present subvertical foliations/lineations, which differ from the magnetic fabric, and higher magmatic anisotropy degree values for amphibole+biotite than plagioclase. Based on numerical simulations of the fluid

  7. Apollo 14 inverted pigeonites - Possible samples of lunar plutonic rocks.

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

    Analysis of 'inverted pigeonites' found in Apollo 14 samples 14082 and 14083 (a polymict breccia, the 'white rock') by a combination of optical, electron probe, and single-crystal X-ray diffraction techniques. These 'inverted pigeonites' are regarded as samples of plutonic rocks that have been blasted out of the Imbrium Basin. It is also concluded that lunar pigeonites will invert to orthopyroxenes, given sufficiently slow cooling histories even in very anhydrous environments.

  8. Nd and Sr isotopic signatures of Mesozoic plutons in northeastern North America

    SciTech Connect

    Foland, K.A.; Jiang-feng, C.; Gilbert, L.A.; Hofmann, A.W.

    1988-08-01

    Nd and Sr initial isotope ratios are reported for 17 Mesozoic plutons of the Monteregian Hills and White Mountain series provinces in northeastern North America. Some variation in the isotopic ratios at most localities is caused by crustal-contamination processes. When the crustal assimilation effects are taken into account, the initial ratios for apparently uncontaminated, mantle-derived parental magmas show only restricted range in /sup 87/Sr//sup 86/Sr (0.7032 to 0.7040) and epsilon/sub Nd/ (T) (+5.4 to +2.3), which are inversely correlated. These ratios characterize alkaline to subalkaline magmas emplaced over more than 400 km/sup 2/ and about 80 m.y. The isotopic and trace-element characteristics are broadly similar to those of many modern ocean-island basalts, specifically the New England Seamounts, suggesting similar time-integrated, lithophile-element-depleted mantle sources. The results are consistent with plume-related mantle sources deeper than the subcontinental mantle.

  9. Isolation and Characterization of Flavanone Glycoside 4I,5, 7-Trihydroxy Flavanone Rhamnoglucose from Garcinia kola Seed

    NASA Astrophysics Data System (ADS)

    Okwu, D. E.; Morah, F. N. I.

    The ethanolic extract of Garcinia kola, Heckel (Guttiferae), which had previously been shown to have biological activity were studied. Preliminary phytochemical screening of the plants showed the presence of flavonoids, phenolic compounds, tannins and saponins. The ethanolic extract of Garcinia kola seeds resulted in the isolation and characterization of flavanone glycoside 4I, 5, 7-trihydroxyflavonone rhamnoglucose (that is naringin-7-rharmnoglucoseside) from its spectral data. IHNMR spin system analysis and acid hydrolysis were performed to characterize the higher order rhamnoglucosyl moiety comprising glucose and rhamnose linked to carbon 7 of the flavanone ring system of the isolate. It is concluded that 4I, 5, 7-trihydroxyflavanone rhamnoglucose may be a contributor to the antioxidants, anti-inflammatory, anti-microbial, anti-tumor and anti-hepatotoxic properties exhibited by Garcinia kola seed.

  10. Alkaline battery operational methodology

    DOEpatents

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  11. Deeply Eroded Massif Anorthosite and Nepheline Syenite of the Chimakurti-Uppalapadu Plutons, Peninsular India: Cospatial but not Comagmatic

    NASA Astrophysics Data System (ADS)

    Kumar, K.; Frost, C. D.; Frost, B. R.

    2001-12-01

    Massif anorthosites are generally thought to be ultimately of mantle origin. However, the lack of samples representing primitive liquid compositions and paucity of early cumulates limits the understanding of the processes that produced them. Some of the most deeply eroded massif anorthosite complexes are exposed within the southern Eastern Ghat Belt of Peninsular India, and provide an excellent opportunity to study the processes that operated in the deep magma chambers beneath the massifs. In this area Si-undersaturated nepheline syenites are associated with anorthosite complexes, a case that is not reported elsewhere in the world. The objectives of the present study are two fold: 1) to identify the processes that acted at the lowest level of the anorthosite complexes and 2) to determine the relationship between cospatial anorthosites and nepheline syenites. Cospatial alkaline-tholeiitic magmatism is strikingly displayed in the Chimakurti-Uppalapadu plutons within Prakasam Province. The Chimakurti pluton is concentrically zoned, and from core to margin consists of 1) olivine clinopyroxenite, 2) anorthosite, 3) olivine gabbronorite and 4) gabbronorite. It emplaced at mid-crustal depths (~6 kb; 16-18 km) and is undeformed and unmetamorphosed. Comparably deep-seated massifs are strongly metamorphosed (Adirondacks) and unmetamorphosed ones typically have shallow emplacement histories (Laramie). Unlike many massif anorthosite complexes, the Chimakurti pluton is associated with a gravity high of the order of 20 to 30 mGal; consistent with the presence of ultramafic cumulates. The Uppalapadu pluton is composed of nepheline syenite (NS). An arcuate band of hornblende syenite with pockets of quartz syenite and ferro-syenite (HQF series) is present between the two plutons. Field, petrographic, mineralogical and geochemical evidence suggests that the Clinopyroxenite-Anorthosite-Gabbro (CAG) suite of Chimakurti is formed by crystal-liquid fractionation (compounded by

  12. Comprehensive paleoseismic geological studies in a key site in southwestern Kola Peninsula (Northeast of the Fennoscandian Shield)

    NASA Astrophysics Data System (ADS)

    Nikolaeva, S. B.; Nikonov, A. A.; Shvarev, S. V.; Rodkin, M. V.

    2016-07-01

    This paper considers the results of detailed paleoseismic and geological investigations in a key site in the wall of the Imandra Lake depression (Kola Peninsula Region, Northeast of the Fennoscandian Shield). Study of different groups of paleoseismic deformations developed in the fault zone and the application of new methods and techniques made it possible to identify a large seismotectonic zone characterized by great earthquakes at the end of the Late Glacial and in the Holocene. The investigation data are indicative of the necessity to estimate the seismic potential in the Kola Atomic plant area in a different way.

  13. Origin and evolution of calcalkaline plutons in the Northeast Kingdom batholith, Vermont

    SciTech Connect

    Ayuso, R.A.; Arth, J.G.

    1985-01-01

    Geochemical and petrographic study of five calcalkaline Devonian plutons in the Northeast Kingdom batholith suggests that they were generated from similar sources but evolved differently. The modally homogeneous Willoughby granite (WG) and the Derby granodiorite (DG) are the most aluminous plutons and contain muscovite and biotite (+/- garnet). The West Charleston diorite (WCD) and the Nulhegan granodiorite (NG) are relatively mafic plutons containing pyroxene, hornblende, and biotite. The Echo Pond (EP) has a granodioritic core but is dioritic along its southern margin. Regular variations of major and trace elements are found in NG and in the relatively sodic DG. More erratic chemical variations are found for WG. The more mafic plutons have higher Sr and lower Rb, Nb and Ta compared to the more felsic WG and DG. Rare-earth patterns for all plutons show higher light than heavy rare-earths. However, the more mafic plutons are comparatively less enriched, have smaller Eu anomalies, and tend to have higher contents of heavy rare earths than the WG and DG. The felsic Willoughby pluton is the best candidate for an upper crustal minimum melt. A deeper origin for the more mafic plutons is likely. Significant differences in the rare earths and ferromagnesian elements indicate that the WG, DG, and EP cannot be related by a simple fractionation scheme to the more mafic plutons.

  14. Why are plutons dry? Outgassing mechanisms of crustal magmatic bodies

    NASA Astrophysics Data System (ADS)

    parmigiani, andrea; Huber, Christian; Bachmann, Olivier; Leclaire, Sébastien

    2016-04-01

    Magma bodies crystallizing to completion within the crust (i.e., forming plutons) typically undergo significant amounts of second boiling (i.e. cooling and crystallization of dominantly anhydrous minerals lead to volatile saturation and bubble nucleation/growth). The low water content (< 1 wt % H2O) and vanishing residual porosity of most plutons, despite the high volatile concentrations of their magma sources (commonly > 6 wt % H2O for evolved compositions in subduction zones), testify that outgassing from crystalline mushy reservoirs must be an efficient and widespread process. Understanding this outgassing mechanism is key to understand how volatiles are transferred from mantle depths to the surface. From the hydrodynamics point of view, the mass balance of exsolved volatiles in these plutonic bodies is controlled by the difference between the rate of degassing (formation of bubbles by 2nd boiling) and outgassing (transport of gas out of the magma body). In this study, we use pore-scale multiphase modeling to constrain these rates as function of the crystal and volatile contents in the magma. Because second boiling is a slow process, one can consider equilibrium degassing as a valid assumption. Outgassing, on the other end, is controlled by the competition between buoyancy, capillary and viscous forces. Our numerical simulations are used to determine the most efficient setting for gas to escape its magmatic trap. The high viscosity of interstitial melts and capillary forces (due to the non-wetting nature of the gas phase with most of the mineral phases in magmatic systems) strongly limits gas transport until vertically extensive gas channels are generated. We show that channels can readily form in volatile-rich coarse-grained mush zones in the upper crust, and allow efficient outgassing at crystallinities around 50-75 vol%, when millimetric bubbles can still win capillary resistive forces.

  15. Geochronology, geochemistry and origins of the Paleozoic-Triassic plutons in the Langshan area, western Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Wang, Zeng-Zhen; Han, Bao-Fu; Feng, Li-Xia; Liu, Bo

    2015-01-01

    The Langshan area is the northeastern part of the Alxa block and adjacent to the Inner Mongolia-Da Hinggan Orogenic Belt (IMDOB) to the north, and geochronological and geochemical studies of the Langshan plutons would be helpful for unraveling the relationship of the magmatism in the Langshan area with that in the IMDOB. Based on zircon U-Pb ages presented in this study and in published papers, five magmatic stages are recognized in Langshan area: Late Silurian (∼418 Ma), Carboniferous (328-304 Ma), Early Permian (294-272 Ma), Late Permian (260-254 Ma) and Middle-Late Triassic (245-227 Ma). The Late Silurian two-mica granite is peraluminous and has a source from ancient continental crust, indicating a collision event. The late Early Carboniferous mafic plutons are subalkaline, show appinitic affinities, and may originate from the subduction-modified continental lithospheric mantle. The late Early Permian granodiorite is weakly peraluminous and high-K calc-alkaline and may be derived from ancient continental crust, while the late Early Permian alkaline gabbro-diorite displays EM I-like Sr-Nd isotopic signatures, indicating an enriched subcontinental lithospheric mantle source. The Late Permian granodiorite is calc-alkaline and peraluminous and may result from the partial melting of ancient lower continental crust, whereas the Late Permian leuconorite belongs to low-K tholeiitic series and has a cumulate origin from an enriched mantle source with the input of juvenile mantle materials. The Paleozoic-Triassic magmatic stages in the Langshan area are consistent with the main magmatic periods in the northern NCC, which are the Late Silurian to Middle Devonian (∼418-386 Ma) and Early Carboniferous to Late Triassic (∼342-211 Ma, with three magmatic stages of Carboniferous, Permian and Triassic). Especially, the Carboniferous to Late Triassic magmatic period in the northern NCC are closely comparable with that in the IMDOB, indicating the two domains might be

  16. In Vitro Antilisterial Properties of Crude Methanol Extracts of Garcinia kola (Heckel) Seeds

    PubMed Central

    Penduka, Dambudzo; Okoh, Anthony I.

    2012-01-01

    Crude methanol extracts of Garcinia kola (Heckel) seeds were screened for their antilisterial activities against 42 Listeria bacteria isolated from wastewater effluents. The extract had activity against 45% of the test bacteria and achieved minimum inhibitory concentrations (MICs) ranging between 0.157 and 0.625 mg/mL. The rate of kill of the extract was determined against four representative Listeria species in the study, and the results showed that the highest percentage of bacteria cells were killed after the maximum exposure time of 2 h at the highest concentration of 4 × MIC value, with the maximum number of bacteria cells killed being for L. ivanovii (LEL 30) 100%, L. monocytogenes (LAL 8) 94.686%, L. ivanovii (LEL 18) 60.330%, and L. grayi (LAL 15) 56.071% We therefore conclude that the nature of inhibition of the crude methanol extracts of Garcinia kola seeds can be either bactericidal or bacteriostatic depending on the target Listeria species and can also differ among same species as evidenced by L. ivanovii strains LEL 30 and LEL 18. PMID:22927786

  17. Widespread tannin intake via stimulants and masticatories, especially guarana, kola nut, betel vine, and accessories.

    PubMed

    Morton, J F

    1992-01-01

    Tannins are increasingly recognized as dietary carcinogens and as antinutrients interfering with the system's full use of protein. Nevertheless, certain tannin-rich beverages, masticatories, and folk remedies, long utilized in African, Asiatic, Pacific, and Latin American countries, are now appearing in North American sundry shops and grocery stores. These include guarana (Paullinia cupana HBK.) from Brazil, kola nut (Cola nitida Schott & Endl. and C. acuminata Schott & Endl.) from West Africa, and betel nut (Areca catechu L.) from Malaya. The betel nut, or arecanut, has long been associated with oral and esophageal cancer because of its tannin content and the tannin contributed by the highly astringent cutch from Acacia catechu L. and Uncaria gambir Roxb. and the aromatic, astringent 'pan' (leaves of Piper betel L.) chewed with it. In addition to the constant recreational/social ingestion of these plant materials, they are much consumed as aphrodisiacs and medications. Guarana and kola nut enjoy great popularity in their native lands because they are also rich in caffeine, which serves as a stimulant. Research and popular education on the deleterious effects of excessive tannin intake could do much to reduce the heavy burden of early mortality and health care, especially in developing countries. PMID:1417698

  18. Petrochemistry and petrology of I-type granitoids in an arc setting: the composite Torul pluton, Eastern Pontides, NE Turkey

    NASA Astrophysics Data System (ADS)

    Kaygusuz, Abdullah; Siebel, Wolfgang; Şen, Cüneyt; Satir, Muharrem

    2008-07-01

    The Upper Cretaceous Torul pluton, located in the Eastern Pontides, is of sub-alkaline affinity and displays features typical of volcanic arc granitoids. It is a composite pluton consisting of granodiorite, biotite hornblende monzogranite, quartz monzodiorite, quartz monzonite and hornblende biotite monzogranite. The oldest syenogranite (77.9 ± 0.3 Ma) and the youngest quartz diorite form small stocks within the pluton. Samples from the granodiorites, biotite hornblende monzogranites, quartz monzodiorites, quartz monzonites and hornblende biotite monzogranites have SiO2 between 57 and 68 wt% and display high-K calc-alkaline, metaluminous to peraluminous characteristics. Chondrite-normalized REE patterns are fractionated (Lacn/Lucn = 6.0-14.2) with pronounced negative Eu anomalies (Eu/Eu* = 0.59-0.84). Initial ɛNd(i) values vary between -3.1 and -4.1, initial 87Sr/86Sr values between 0.7058 and 0.7072, and δ18O values between +4.4 and +7.3‰. The quartz diorites are characterized by relatively high Mg-number of 36-38, low contents of Na2O (2.3-2.5 wt%) and SiO2 (52-55 wt%) and medium-K calc-alkaline, metaluminous composition. Chondrite-normalized REE patterns are relatively flat [(La/Yb)cn = 2.8-3.3; (Tb/Yb)cn = 1.2] and show small negative Eu anomalies (Eu/Eu* = 0.74-0.76). Compared to the other rock types, radiogenic isotope signatures of the quartz diorites show higher 87Sr/86Sr (0.7075-0.7079) and lower ɛNd(i) (-4.5 to -5.3). The syenogranites have high SiO2 (70-74 wt%) and display high-K calc-alkaline, peraluminous characteristics. Their REE patterns are characterized by higher Lacn/Lucn (12.9) and Eu/Eu* (0.76-0.77) values compared to the quartz diorites. Isotopic signatures of these rocks [ɛNd(i) = -4.0 to -3.3; 87Sr/86Sr(i) = 0.7034-0.7060; δ18 O = + 4.9 to + 8.2] are largely similar to the other rock types but differ from that of the quartz diorites. Fractionation of plagioclase, hornblende, pyroxene and Fe-Ti oxides played an important role in the

  19. The Crabtree Creek pluton: A deformed Mid-Paleozoic( ) stitching pluton on the west flank of the Raleigh metamorphic belt

    SciTech Connect

    Blake, E.F. . Dept. of Earth Sciences); Stoddard, E.F. . Dept. of MEAS)

    1993-03-01

    Crystalline rocks on the west flank of the Alleghanian-aged Raleigh metamorphic belt are subdivided into four west-dipping lithotectonic terranes in the Falls Lake and north Raleigh areas. The rocks of these terranes are separated from east to west on the basis of bulk rock composition, metamorphic textural characteristics, and discrete structural discontinuities into the Raleigh terrane (RT), Crabtree terrane (CT), Falls Lake melange (FLM), and the volcanogenic Carolina slate belt (CSB). The RT and CT are separated by the dextral shear Nutbush Creek fault zone, while the Falls Lake thrust juxtaposes the CT and FLM. The structural character of the discontinuity separating the FLM and the CSB is unclear, although thrusting has been proposed. The results of geologic mapping in the Raleigh West 7.5[prime] quadrangle for the NC Geological Survey's COGEOMAP project in the Raleigh 1[degree] sheet indicate that only the CSB and CT are exposed west of I-440 between US 70 and I-40. This confirms the mapping results of Horton and others that the melange pinches out in north Raleigh just north of US 70. South of US 70, a large orthogneiss body, the Crabtree Creek composite granitic pluton, occupies the same relative position as the melange, separating mafic and intermediate metavolcanic rocks of the CSB from nonlineated and lineated interlayered schists and gneisses of the CT. The pluton is subdivided into a foliated leucocratic, medium grained muscovite granitic orthogneiss, and a foliated leucocratic to mesocratic medium to coarse grained muscovite [plus minus] biotite granitic orthogneiss containing abundant porphyroclastic disks, rods, and knobs of quartz. Because its lobes locally display intrusive contacts with metavolcanic and metasedimentary rocks of both terranes, the Crabtree Creek pluton represents an intrusion that stitched the two terranes together.

  20. Les granitoïdes néoprotérozoïques de Khzama, Anti-Atlas central, Maroc: marqueurs de l'évolution d'un magmatisme d'arc à un magmatisme alcalineNeoproterozoic granitoids from Khzama, central Anti-Atlas, Morocco: evolution markers from arc magmatism to alkaline magmatism

    NASA Astrophysics Data System (ADS)

    El-Khanchaoui, T.; Lahmam, M.; El-Boukhari, A.; El-Beraaouz, H.

    2001-05-01

    Petrological study and zircon typology provide important information that is related to the classification and genesis of Neoproterozoic granitoids in the Khzama area (northeast Siroua). The Pan-African granitoids show a transition from island-arc magmatism to alkaline magmatism. A space and time zonation of magmatism from the north to the south is evident. Early Pan-African granitoids were generated from various magma sources through different petrogenetic mechanisms. The first association corresponds to the low-K calc-alkaline plutons of Ait Nebdas, the second one correponds to high-K calc-alkaline post-collisional granites (Tamassirte-Tiferatine and Ifouachguel). Finally, shoshonitic magmatism (Irhiri) ends the magmatic evolution of the region. Thus, the late Pan-African granitic plutonism began with calc-alkaline associations and ended with K-alkaline magmatism in a transtensional setting, heralding the onset of the Moroccan Palæozoic cycle.

  1. Impact of acid and trace metals deposition on freshwater invertebrates in north-eastern Fennoscandia and Kola Peninsula

    SciTech Connect

    Yakovlev, V.

    1996-12-31

    Freshwater invertebrate communities in a total 400 lakes and streams in northeastern Norway, Finnish Lapland and the Kola Peninsula, subjected to the atmospheric deposition were studied. The severe influence of toxic heavy metals, dusts from smelters and mineral enrichment factories were found in the Kola Peninsula. The negative acidification effects on benthic communities were found in the Jarfjord (Norway), Enontekio, Ranua-Posio and Kittila-Kolari (Finnish Lapland) areas and in the Kola Peninsula (Russia). Taxa groups, known to be sensitive to acidification, such as gammarids, snails, mayflies, stone flies, were represented with few species and in a low abundance. Heavy metals accumulation in biota is recorded in areas surrounding nickel smelters in the Kola Peninsula. The metal concentration invertebrates in remote areas is rather wide and depend on an air deposition, characteristics of lake catchment areas, as well as water acidity. The environmental variables, such as lake hydrological type, altitude of lakes, dominant substratum type, abundance of macrophytes and mosses in sampling area, content of pollutants in water also show significant relationships with metal concentration in invertebrates. The most severe negative effects on biota were found in waters with low pH and simultaneously contaminated by heavy metals. The biological method for estimation of simultaneously water acidification and contamination is suggested.

  2. Sheeted and bulbous pluton intrusion mechanisms of a small granitoid from southeastern Australia: implications for dyke-to-pluton transformation during emplacement

    NASA Astrophysics Data System (ADS)

    Fowler, T. J.

    1994-06-01

    The small late syn-tectonic Carboniferous Davys Creek Granite (DCG) of southeastern Australia consists of microgranitic intrusive bodies of diverse geometry and structure. These bodies include: (1) subvertical concordant sheets; (2) bulbous peneconcordant plutons with apophyses and discordant lobes; and (3) subvertical dykes and stocks. The sequence of changing intrusive style is broadly 1-2-3. Transition from 1 to 2 was probably a response to rising magma pressures or declining tectonic stresses. The λ parameter of Emerman and Marrett (1990), which discriminates between stable sheet-like and potential stock/pluton/batholith emplacement modes, adequately predicts the transitions between sheet and pluton emplacements for the DCG. Ductile dyking along actively forming foliations appears to have been an important early intrusive mechanism. A transition from sheet to bulbous pluton intrusion style is suggested to have been in response to magma pressure increases.

  3. Interactions between plutonism and detachments during metamorphic core complex formation, Serifos Island (Cyclades, Greece)

    NASA Astrophysics Data System (ADS)

    Rabillard, Aurélien; Arbaret, Laurent; Jolivet, Laurent; Le Breton, Nicole; Gumiaux, Charles; Augier, Romain; Grasemann, Bernhard

    2015-06-01

    In order to better understand the interactions between plutonic activity and strain localization during metamorphic core complex formation, the Miocene granodioritic pluton of Serifos (Cyclades, Greece) is studied. This pluton (11.6-9.5 Ma) intruded the Cycladic Blueschists during thinning of the Aegean domain along a system of low-angle normal faults belonging to the south dipping West Cycladic Detachment System (WCDS). Based on structural fieldwork, together with microstructural observations and anisotropy of magnetic susceptibility, we recognize a continuum of deformation from magmatic to brittle conditions within the magmatic body. This succession of deformation events is kinematically compatible with the development of the WCDS. The architecture of the pluton shows a marked asymmetry resulting from its interaction with the detachments. We propose a tectonic scenario for the emplacement of Serifos pluton and its subsequent cooling during the Aegean extension: (1) A first stage corresponds to the metamorphic core complex initiation and associated southwestward shearing along the Meghàlo Livadhi detachment. (2) In the second stage, the Serifos pluton has intruded the dome at shallow crustal level, piercing through the ductile/brittle Meghàlo Livadhi detachment. Southwest directed extensional deformation was contemporaneously transferred upward in the crust along the more localized Kàvos Kiklopas detachment. (3) The third stage was marked by synmagmatic extensional deformation and strain localization at the contact between the pluton and the host rocks resulting in nucleation of narrow shear zones, which (4) continued to develop after the pluton solidification.

  4. Emplacement, rapid burial, and exhumation of 90-Ma plutons in southeastern Alaska

    USGS Publications Warehouse

    Himmelberg, G.R.; Haeussler, P.J.; Brew, D.A.

    2004-01-01

    In southeastern Alaska, granodiorite-tonalite plutons of the Admiralty-Revillagigedo belt intruded the Jurassic-Cretaceous Gravina belt along the eastern side of the Alexander terrane around 90 Ma. These plutons postdate some deformation related to a major contractional event between the previously amalgamated Wrangellia and Alexander terranes and the previously accreted terranes of the North American margin. We studied the aureole mineral assemblages of these plutons near Petersburg, Alaska, determined pressure and temperature of equilibration, and examined structures that developed within and adjacent to these plutons. Parallelism of magmatic and submagmatic fabrics with fabrics in the country rock indicates synchroneity of pluton emplacement with regional deformation and suggests that magma transport to higher crustal levels was assisted by regional deformation. Replacement of andalusite by kyanite or sillimanite indicates crustal thickening soon after pluton emplacement. Regional structural analysis indicates the crustal thickening was accomplished by thrust burial. Thermobarometric analyses indicate the aureoles reached near-peak temperatures of 525 to 635 ??C at pressures of 570 to 630 MPa. Consideration of the rate of thermal decay of the aureoles suggests that burial was rapid and occurred at rates around 5 to 8 mm/year. Structural observations indicate there was contractional deformation before, during, and after emplacement of the 90-Ma plutons. Initial exhumation of the Admiralty-Revillagedo belt in the Petersburg area may have occurred along a thrust west of the pluton belt within the Gravina belt. ?? 2004 NRC Canada.

  5. Three-dimensional shape and emplacement of the Cardenchosa deformed pluton (Variscan Orogen, southwestern Iberian Massif)

    NASA Astrophysics Data System (ADS)

    Simancas, J. Fernando; Galindo-Zaldívar, Jesús; Azor, Antonio

    2000-04-01

    The Cardenchosa pluton is a Lower Carboniferous Variscan granite located in the southwestern Iberian Massif. It intruded along the contact between the Sierra Albarrana and Azuaga tectonic units. To the northwest the pluton connects with the left-lateral Azuaga fault. The pluton appears in the footwall of the low-angle normal Casa del Café fault, which crops out to the west of the granite. Gravimetric modelling shows the pluton to have a flat bottom at a depth of 2 km. Strain analysis of post-emplacement deformation of the pluton indicates that: (a) the deformation of the pluton accommodates the displacement of the Azuaga fault; and (b) the pluton prior to the solid state deformation was a lens-shaped laccolith of approximately 10 km diameter and 2 km thickness. The Cardenchosa pluton was a single pulse of magma trapped in a rheological discontinuity of the upper crust (the contact between the Sierra Albarrana and Azuaga units). The magma would ascend through dikes since no root has been detected. The tectonic scenario during the intrusion was one of regional extension.

  6. Guidelines to classification and nomenclature of Arabian felsic plutonic rocks

    USGS Publications Warehouse

    Ramsay, C.R.; Stoeser, D.B.; Drysdall, A.R.

    1986-01-01

    Well-defined procedures for classifying the felsic plutonic rocks of the Arabian Shield on the basis of petrographic, chemical and lithostratigraphic criteria and mineral-resource potential have been adopted and developed in the Saudi Arabian Deputy Ministry for Mineral Resources over the past decade. A number of problems with conventional classification schemes have been identified and resolved; others, notably those arising from difficulties in identifying precise mineral compositions, continue to present difficulties. The petrographic nomenclature used is essentially that recommended by the International Union of Geological Sciences. Problems that have arisen include the definition of: (1) rocks with sodic, zoned or perthitic feldspar, (2) trondhjemites, and (3) alkali granites. Chemical classification has been largely based on relative molar amounts of alumina, lime and alkalis, and the use of conventional variation diagrams, but pilot studies utilizing univariate and multivariate statistical techniques have been made. The classification used in Saudi Arabia for stratigraphic purposes is a hierarchy of formation-rank units, suites and super-suites as defined in the Saudi Arabian stratigraphic code. For genetic and petrological studies, a grouping as 'associations' of similar and genetically related lithologies is commonly used. In order to indicate mineral-resource potential, the felsic plutons are classed as common, precursor, specialized or mineralized, in order of increasing exploration significance. ?? 1986.

  7. Crystal structure of hydrogen-bearing vuonnemite from the Lovozero alkaline massif

    SciTech Connect

    Rastsvetaeva, R. K. Aksenov, S. M.; Verin, I. A.; Lykova, I. S.

    2011-05-15

    Hydrogen-bearing vuonnemite from the Shkatulka hyperagpaitic pegmatite (the Lovozero alkaline massif, Kola Peninsula) was studied by single-crystal X-ray diffraction. The triclinic unit-cell parameters are as follows: a = 5.4712(1) Angstrom-Sign , b = 7.1626(1) Angstrom-Sign , c = 14.3702(3) Angstrom-Sign , {alpha} = 92.623(2) Degree-Sign , {beta} = 95.135(1) Degree-Sign , {gamma} = 90.440(1) Degree-Sign , sp. gr. P1, R = 3.4%. The Na{sup +} cations and H{sub 2}O molecules are ordered in sites between the packets. The water molecules are hydrogen bonded to the PO{sub 4} tetrahedra.

  8. Comparative study on the efficacy of Garcinia kola in reducing some heavy metal accumulation in liver of Wistar rats.

    PubMed

    Nwokocha, C R; Owu, D U; Ufearo, C S; Iwuala, M O E

    2011-05-17

    Garcinia kola is regarded as an antidote and anti-hepatotoxic agent. We examined its protection ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. The ground seed was mixed with rat feed (5%, w/w) and fed to rats while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Garcinia kola was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. The heavy metal accumulations in the liver were determined using AAS. Garcinia kola could not reverse the weight reduction in the heavy metal exposed groups although it offers more protection and aid greater elimination of heavy metals from the liver. There was a significant (P<0.01) increase in protection by Garcinia kola to Cd (72.4%) and Pb (56.2%) accumulation when compared to Hg (40%) at week 2 which was significantly (P<0.01) decreased at week 4 when compared to week 2. At week 6, the percentage protection to both Hg (64.2%) and Cd (62.2%) were comparable to each other while protection to Pb (49.9%) accumulation was significantly (P<0.01) reduced. The percentage protection was time-dependent in some groups but treatment during and after the exposure provided a greater protection. Garcinia kola has the highest hepatoprotective effect to Cd followed by Hg and least protection against Pb toxicity in rats and its administration is beneficial in reducing heavy metal accumulation in the liver. PMID:21458555

  9. Age and intrusive relations of the Lamarck granodiorite and associated mafic plutons, Sierra Nevada, California

    SciTech Connect

    Joye, J.L.; Bachl, C.A.; Miller, J.S.; Glazner, A.F. . Dept. of Geology); Frost, T.P. ); Coleman, D.S. . Dept. of Earth, Atmospheric and Planetary Sciences)

    1993-04-01

    The compositionally zoned Late Cretaceous Lamarck granodiorite, west of Bishop, hosts numerous mafic intrusions ranging from hornblende gabbro to mafic granodiorite. Frost and Mahood (1987) suggested from field relations that the Lamarck and the associated mafic plutons were co-intrusive. Contact relations between the Lamarck host and the mafic intrusions are variable (sharp to diffuse) and in places suggest commingling. In order to constrain the intrusive relationships between the Lamarck and its associated mafic plutons, the authors have analyzed feldspars from the Mt. Gilbert pluton and the Lamarck granodiorite to see if feldspar compositions in the Mt. Gilbert overlap those in the Lamarck host and determined U-Pb zircon ages for the Mt. Gilbert and Lake Sabrina plutons to see if they have the same age as the Lamarck granodiorite. Feldspars from the Lamarck granodiorite are normally zoned and range compositionally from An[sub 38--32]; those in the Mt. Gilbert diorite are also normally zoned but range compositionally from An[sub 49--41] and do not overlap the Lamarck host. Four to five zircon fractions from each pluton were handpicked and dated using U-Pb methods. The Mt. Gilbert mafic diorite has a concordant age of 92.5 Ma and the Lake Sabrina diorite has a concordant age of 91.5 Ma. Ages for the two plutons overlap within error, but multiple fractions from each suggest that the Lake Sabrina pluton is slightly younger than the Mt. Gilbert pluton. These data and field relationships indicate: (1) plagioclase phenocrysts in the Mt. Gilbert pluton were not derived from the Lamarck granodiorite despite their textural similarity; but (2) the Lamarck granodiorite and its associated mafic plutons are co-intrusive as supported by the close agreement of the ages with the crystallization age obtained by Stern and others for the Lamarck granodiorite.

  10. Alkaline flooding injection strategy

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1992-03-01

    The objective of this project is to improved alkali-surfactant flooding methods, and this includes determining the proper design of injection strategy. Several different injection strategies have been used or suggested for recovering heavy oils with surfactant-enhanced alkaline flooding methods. Oil recovery was compared for four different injection strategies: (1) surfactant followed by polymer, (2) surfactant followed by alkaline polymer, (3) alkaline surfactant followed by polymer, and (4) alkali, surfactant, and polymer mixed in a single formulation. The effect of alkaline preflush was also studied under two different conditions. All of the oil recovery experiments were conducted under optimal conditions with a viscous, non-acidic oil from Hepler (KS) oil field. The coreflood experiments were conducted with Berea sandstone cores since field core was not available in sufficient quantity for coreflood tests. The Tucker sand of Hepler field is a Class I fluvial dominated deltaic reservoir, as classified by the Department of Energy, which has been selected as the site of a DOE-sponsored field pilot test.

  11. ABCGheritage project - promoting geotourism in northern Finland, northern Norway and the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Pihlaja, Jouni; Johansson, Peter; Lauri, Laura S.

    2014-05-01

    Nature tourism has been a growing business sector in the Barents area during the recent decades. With the purpose to develop nature tourism in a sustainable way, a cooperation project ABCGheritage - Arctic Biological, Cultural and Geological Heritage has been carried out. Project has received partial funding from the EU Kolarctic ENPI program. In the geoheritage part of the project the main activities were aimed to develop pro-environmental ways of geotourism in the area. The three main participants in the geoheritage part of the project are the Geological Survey of Finland, Northern Finland Office, the Geological Institute of the Kola Science Centre of the Russian Academy of Sciences and Bioforsk Soil and Environment from northeastern Norway. The duration of the project is 2012-2014 and most of the work has already been completed even if most of the results are not published yet. Totally ten different tasks have been implemented in the geological part of the project. The largest task has been the preparation of a geological outdoor map and guide book of the Khibiny Tundra locating in the central part of the Kola Peninsula. In Finland already 11 such maps have been published, and the experiences gained during their production have been used in this project, too. Geological heritage trails to the Khibiny Tundra have also been created and they will be drawn on the map. The second concrete result is the Barents Tour for Geotourist -guide, which will be published as a guide book, web pages and an exhibition. The route comprises ca 35 best geological demonstration sites along the circle route from northern Finland to northeastern Norway, from there to Kola Peninsula and then back to Finland. Information of the route will be available for all interested travelers. In addition to the geological outdoor map of the Khibiny Tundra and "Barents Tour for Geotourists"-guide, the primary outputs of the project are the geological nature trails on the field, geological

  12. Melt segregation evidence from a young pluton, Takidani Granodiorite (Japan)

    NASA Astrophysics Data System (ADS)

    Hartung, Eva; Caricchi, Luca; Floess, David; Wallis, Simon; Harayama, Satoru; Chiaradia, Massimo; Kouzmanov, Kalin

    2016-04-01

    We are presenting new petrological data from one of the youngest exposed plutons in the world, the Takidani Granodiorite (Japan), which has been suggested as a source for large volume ignimbrites (> 300km3). Takidani Granodiorite (1.54 Ma ± 0.23 Ma) is located within the active Norikura Volcanic Chain in the Northen Japan Alps and has been previously linked to large andesitic (1.76 Ma ± 0.17 Ma) and rhyolitic eruptions (1.75 Ma ± 0.17 Ma). The pluton is vertically zoned and consists of granites (67 to 68 wt.% SiO2) in the lower section, granodiorites (65 to 66 wt.% SiO2) in the middle section, a chemically more evolved fine-grained porphyritic unit (67 to 71 wt.% SiO2) near the roof and a marginal granodiorite at the roof (67 to 68 wt.% SiO2). The porphyritic texture of the more evolved unit near the roof indicates rapid crystallisation, which could be the result of the late intrusion of this unit at the roof of the magmatic system. However, no sharp contact is found between the underlying granodiorite and the porphyritic unit. Instead, a gradual change in rock fabric, whole-rock chemistry and mineralogy is observed suggesting that melt was extracted from the granodiorite. Electron microprobe analyses of plagioclases show three main crystal populations (Type I, II and III) with distinct anorthite and Fe contents. Type I plagioclase (An30‑40) occurs dominantly within the marginal granodiorite at the roof. Type II plagioclase (An40‑45) are common in the granodiorite and porphyritic unit. Type III plagioclase (An45‑50) is predominantly present in the granite. All plagioclase populations share a common sodic rim (An22) across the different units. Takidani Granodiorite rocks are compared to crystallisation experiments from similar magmatic suites. Emplacement conditions of the Takidani Granodiorite are obtained from the latter as well as barometry, thermometry and hygrometry indicating that magmas were ultimately emplaced at around 200 MPa, 850° C to 875° C

  13. The primary circuit materials properties results analysis performed on archive material used in NPP V-1 and Kola NPP Units 1 and 2

    SciTech Connect

    Kupca, L.; Beno, P.

    1997-04-01

    A very brief summary is provided of a primary circuit piping material properties analysis. The analysis was performed for the Bohunice V-1 reactor and the Kola-1 and -2 reactors. Assessment was performed on Bohunice V-1 archive materials and primary piping material cut from the Kola units after 100,000 hours of operation. Main research program tasks included analysis of mechanical properties, corrosion stability, and microstructural properties. Analysis results are not provided.

  14. Paleomagnetism of Devonian dykes in the northern Kola Peninsula and its bearing on the apparent polar wander path of Baltica in the Precambrian

    NASA Astrophysics Data System (ADS)

    Veselovskiy, Roman V.; Bazhenov, Mikhail L.; Arzamastsev, Andrey A.

    2016-04-01

    Mafic dykes and large alkaline and carbonatite intrusions of Middle-Late Devonian age are widespread on the Kola Peninsula in NE Fennoscandia. These magmatic rocks are well characterized with petrographic, geochemical and geochronological data but no paleomagnetic results have been reported yet. We studied dolerite dykes from the northern part of the Peninsula and isolated three paleomagnetic components in these rocks. A low-temperature component is aligned along the present-day field, while a major constituent of natural remanent magnetization is an intermediate-temperature component (Decl. = 79.6°, Inc. = 78.5°, α95 = 5,9°, N = 17 sites) that is present in most Devonian dykes but is found in some baked metamorphic rocks and Proterozoic dykes too. Finally, a primary Devonian component could be reliably isolated from two dykes only. Rock-magnetic studies point to presumably primary low-Ti titanomagnetite and/or pure magnetite as the main remanence carriers but also reveal alteration of the primary minerals and the formation of new magnetic phases. The directions of a major component differ from the Middle Paleozoic reference data for Baltica but closely match those for the 190 ± 10 Ma interval recalculated from the apparent polar wander path of the craton. We assume that this Early Jurassic component is a low-temperature overprint of chemical origin. The main impact of the new results is not to mid-Paleozoic or Early Mesozoic times but to much older epochs. Analysis of paleomagnetic data shows that the directionally similar remanences are present in objects with the ages ranging from 500 Ma to ~ 2 Ga over entire Fennoscandia. Hence we argue that an Early Jurassic remagnetization is of regional extent but cannot link it to a certain process and a certain tectonic event. If true, this hypothesis necessitates a major revision of the APWP for Baltica over a wide time interval.

  15. Petrological imaging of an active pluton beneath Cerro Uturuncu, Bolivia

    NASA Astrophysics Data System (ADS)

    Muir, Duncan D.; Blundy, Jon D.; Hutchinson, Michael C.; Rust, Alison C.

    2014-03-01

    Uturuncu is a dormant volcano in the Altiplano of SW Bolivia. A present day ~70 km diameter interferometric synthetic aperture radar (InSAR) anomaly roughly centred on Uturuncu's edifice is believed to be a result of magma intrusion into an active crustal pluton. Past activity at the volcano, spanning 0.89 to 0.27 Ma, is exclusively effusive and almost all lavas and domes are dacitic with phenocrysts of plagioclase, orthopyroxene, biotite, ilmenite and Ti-magnetite plus or minus quartz, and microlites of plagioclase and orthopyroxene set in rhyolitic groundmass glass. Plagioclase-hosted melt inclusions (MI) are rhyolitic with major element compositions that are similar to groundmass glasses. H2O concentrations plotted versus incompatible elements for individual samples describe a trend typical of near-isobaric, volatile-saturated crystallisation. At 870 °C, the average magma temperature calculated from Fe-Ti oxides, the average H2O of 3.2 ± 0.7 wt% and CO2 typically <160 ppm equate to MI trapping pressures of 50-120 MPa, approximately 2-4.5 km below surface. Such shallow storage precludes the role of dacite magma emplacement into pre-eruptive storage regions as being the cause of the observed InSAR anomaly. Storage pressures, whole-rock (WR) chemistry and phase assemblage are remarkably consistent across the eruptive history of the volcano, although magmatic temperatures calculated from Fe-Ti oxide geothermometry, zircon saturation thermometry using MI and orthopyroxene-melt thermometry range from 760 to 925 °C at NNO ± 1 log. This large temperature range is similar to that of saturation temperatures of observed phases in experimental data on Uturuncu dacites. The variation in calculated temperatures is attributed to piecemeal construction of the active pluton by successive inputs of new magma into a growing volume of plutonic mush. Fluctuating temperatures within the mush can account for sieve-textured cores and complex zoning in plagioclase phenocrysts

  16. Plutonism, oblique subduction, and continental growth: An example from the Mesozoic of California

    SciTech Connect

    Glazner, A.F. )

    1991-08-01

    Major episodes of Mesozoic plutonism in California correlate with periods of oblique subduction and trench-parallel transport of western California along intrabatholithic faults. Major episodes of plutonism occurred in the Late Jurassic, during left-oblique convergence, and in the mid-Cretaceous, during right-oblique convergence. In contrast, a conspicuous lull in plutonism (but continuation of volcanism) in the earliest Cretaceous coincides with a time when the North America-Farallon convergence vector, although large in magnitude, was oriented perpendicular to the trench. This correlation suggests that plutonism is facilitated by strike-slip faulting within the batholithic belt; one explanation, which helps to solve the plutonic room problem, is that plutons are passively emplaced at releasing bends in the strike-slip faults, and volume is conserved by thrusting at the trench. If this correlation is generally applicable, then it implies that mid-crustal plutonism is limited beneath areas in which the convergence vector is subperpendicular to the trench. Continental growth in such areas may occur dominantly by volcanism.

  17. Cretaceous plutonic rocks in the Donner Lake-Cisco Grove area, northern Sierra Nevada, California

    USGS Publications Warehouse

    Kulow, Matthew J.; Hanson, Richard E.; Girty, Gary H.; Girty, Melissa S.; Harwood, David S.

    1998-01-01

    The northernmost occurrences of extensive, glaciated exposures of the Sierra Nevada batholith occur in the Donner Lake-Cisco Grove area of the northern Sierra Nevada. The plutonic rocks in this area, which are termed here the Castle Valley plutonic assemblage, crop out over an area of 225 km2 and for the most part are shown as a single undifferentiated mass on previously published geological maps. In the present work, the plutonic assemblage is divided into eight separate intrusive units or lithodemes, two of which each consist of two separate plutons. Compositions are dominantly granodiorite and tonalite, but diorite and granite form small plutons in places. Spectacular examples of comb layering and orbicular texture occur in the diorites. U-Pb zircon ages have been obtained for all but one of the main units and range from ~120 to 114 Ma, indicating that the entire assemblage was emplaced in a narrow time frame in the Early Cretaceous. This is consistent with abundant field evidence that many of the individual phases were intruded penecontemporaneously. The timing of emplacement correlates with onset of major Cretaceous plutonism in the main part of the Sierra Nevada batholith farther south. The emplacement ages also are similar to isotopic ages for gold-quartz mineralization in the Sierran foothills west of the study area, suggesting a direct genetic relationship between the voluminous Early Cretaceous plutonism and hydrothermal gold mineralization.

  18. Natural radioactivity levels in granitic plutons and groundwaters in Southeast part of Eskisehir, Turkey.

    PubMed

    Orgün, Y; Altinsoy, N; Gültekin, A H; Karahan, G; Celebi, N

    2005-08-01

    The present work investigated the radioactivity level of the granitoid plutons and its effect on the groundwaters in the southeast part of Eskisehir. Fourteen granitic samples from the Kaymaz and Sivrihisar plutons and 11 groundwater samples from the near vicinity of the pluton were analyzed. The activity concentrations measured for (238)U and (232)Th ranged from 43.59+/-2 to 651.80+/-24 Bq/kg, and 51.16+/-3 to 351.94+/-13 Bq/kg, respectively. The activity concentrations obtained for (40)K varied from 418.50+/-17 to 1618.03+/-66 Bq/kg. The absorbed dose rates in air outdoors ranged from 87.14 to 531.81 nGy/h. All the results obtained from the Kaymaz pluton are higher than those from the Sivrihisar. The U (ave. 16.6 ppm) and Th (ave. 49.9 ppm) values of the Kaymaz pluton are higher than the average concentrations of the magmatic rocks of granitic composition. These results are consistent with high dose rates of the pluton. The gross-alpha activities in the groundwater samples ranged from 0.009 to 1.64 Bq/l and the gross-beta activities from 0.006 to 0.89 Bq/l. The highest gross-alpha value was found in the sample taken from near the Kaymaz pluton. The concentrations of (222)Rn varied from 0.060 to 0.557 Bq/l. PMID:15921915

  19. Zircon U-Pb age, Lu-Hf isotope, mineral chemistry and geochemistry of Sundamalai peralkaline pluton from the Salem Block, southern India: Implications for Cryogenian adakite-like magmatism in an aborted-rift

    NASA Astrophysics Data System (ADS)

    Renjith, M. L.; Santosh, M.; Li, Tang; Satyanarayanan, M.; Korakoppa, M. M.; Tsunogae, T.; Subba Rao, D. V.; Kesav Krishna, A.; Nirmal Charan, S.

    2016-01-01

    The Sundamalai peralkaline pluton is one among the Cryogenian alkaline plutons occurring in the Dharmapuri Rift Zone (DRZ) of the Salem Block in the Southern Granulite Terrane (SGT) of India. Here we present zircon U-Pb age and Lu-Hf isotopic composition, mineral chemistry and geochemistry of the pluton to explore the petrogenesis and geodynamic implications. Systematic modal variation of orthoclase, Na-plagioclase, Ca-amphibole (ferro-edenite and hastingsite) and quartz developed quartz-monzonite and granite litho units in the Sundamalai pluton. Thermometry based on amphibole-plagioclase pair suggests that the pluton was emplaced and solidified at around 4.6 kbar pressure with crystallization of the major phases between 748 and 661 °C. Estimated saturation temperature of zircon (712-698 °C) is also well within this range. However, apatite saturation occurred at higher temperatures between 835 and 870 °C, in contrast with monazite saturation (718-613 °C) that continued up to the late stage of crystallization. Estimated oxygen fugacity values (log fO2: -14 to -17) indicate high oxidation state for the magma that stabilized titanite and magnetite. The magmatic zircons from Sundamalai pluton yielded a weighted mean 206Pb/238U age of 832.6 ± 3.2 Ma. Geochemically, the Sundamalai rocks are high-K to shoshonitic, persodic (Na2O/K2O ratio > 1), silica-saturated (SiO2:65-72 wt.%), and peralkaline in composition (aluminum saturation index, ASI < 1; Alkalinity index, AI < 0). The initial magma was mildly metaluminous which evolved to strongly peralkaline as result of fractional crystallization (plagioclase effect) controlled differentiation between quartz-monzonite and granite. Both rock types have high content of Na2O (5.1-6.3 wt.%), Ba (350-2589 ppm) and Sr (264-1036 ppm); low content of Y (8.7-17 ppm) and Yb (0.96-1.69 ppm); elevated ratios of La/Yb (11-46) and Sr/Y (46-69) and are depleted in Ti, with a positive Sr anomaly suggesting an adakite-like composition and

  20. Climatic variations on longest tree-ring chronologies for Kola Peninsula and Finnish Lapland

    NASA Astrophysics Data System (ADS)

    Kasatkina, E. A.; Shumilov, O. I.; Timonen, M.; Mielikainen, K.; Helama, S.; Kanatjev, A. G.; Kirtsideli, I. Yu.

    2010-05-01

    We investigated the external factor (solar activity, volcanic eruptions) influence on tree growth at high latitudes. We analysed a 561-year tree-ring record of pine (Pinus sylvestris L.) and a 676-year juniper (Juniperus Sibirica Burgst.) tree-ring chronology collected nearby the northern timberline (67.77-68.63N; 33.25-36.52 E) at the Kola Peninsula, northwestern Russia. As well known the climatic impacts of solar and volcanic activity vary regionally, and major volcanic eruptions do not always result in regional cooling. A response of tree growth at the Kola Peninsula to climatic changes due to solar variability and volcanic eruptions was revealed. For example, Dalton minimum of solar activity (1801-1816 AD) and Laki (1783 AD) and Tambora (1815 AD) volcanic eruptions appeared to cause the greatest ring-width reduction and cooling. The minima of solar activity Sporer (1416-1534 AD) and Maunder (1645-1715 AD) were as well accompanied by temperature decreases. Intervals with an absence of significant volcanic eruptions correspond to intervals of increased ring-width values. A superposed epoch analysis of 19 large (Volcanic Explosivity Index, VEI>5) volcanic events revealed a significant suppression of tree growth for up to 8 years following volcanic eruptions. The similar effect (supression of tree growth after powerful volcanic eruptions) was obtained under analysis of the 7641-year supra-long pine tree-ring chronology for Finnish Lapland. Our results documenting the regional climatic impacts of solar and volcanic activity permit us to understand the dynamics of the climate system and its response to external forcing. This work is financially supported by grant from Russian Foundation for Basic Research (grant No. 09-04-98801), by the Program of the Russian Academy and by the Regional Scientific Program of Murmansk region.

  1. An Archean Geomagnetic Reversal in the Kaap Valley Pluton, South Africa

    PubMed

    Layer; Kroner; McWilliams

    1996-08-16

    The Kaap Valley pluton in South Africa is a tonalite intrusion associated with the Archean Barberton Greenstone Belt. Antipodal paleomagnetic directions determined from the central and marginal parts of the pluton record a geomagnetic reversal that occurred as the pluton cooled. The age of the reversal is constrained by an 40Ar/39Ar plateau age from hornblende at 3214 +/- 4 million years, making it the oldest known reversal. The data presented here suggest that Earth has had a reversing, perhaps dipolar, magnetic field since at least 3.2 billion years ago. PMID:8688075

  2. Tectonic setting of the Sandia pluton: An orogenic 1.4 Ga granite in New Mexico

    NASA Astrophysics Data System (ADS)

    Kirby, Eric; Karlstrom, Karl E.; Andronicos, Chris L.; Dallmeyer, R. David

    1995-02-01

    Structural studies of the circa 1.42 Ga Sandia pluton and its aureole document significant deformation synchronous with pluton emplacement and call into question the "anorogenic" label associated with this and other 1.4 Ga granites in the southwestern United States. The SE margin of the pluton is a 1- to 2-km-wide NW dipping ductile shear zone. Field and microstructural observations (melt-filled shear bands, high-temperature dynamic recrystallization of K-feldspar megacrysts, and crosscutting pegmatite dikes) indicate that top-to-the-NW (normal) movement in the shear zone took place in the presence of melt. Subparallel magmatic fabrics north of and structurally above the shear zone contain kinematic indicators consistent with top-to-the-NW shear sense, suggesting that over large regions of the pluton, magmatic flow mimicked solid-state strain. In the northern aureole, contact metamorphic aluminosilicate porphyroblasts grew during the formation of a NE striking crenulation cleavage (S3) and related folds of late-stage pegmatite dikes. These features document the synchroneity of magma emplacement, shortening, and metamorphism and indicate that the Sandia pluton is syntectonic, not anorogenic. We interpret the kinematic consistency of structural elements from the base of the pluton, the interior of the pluton, and the northern aureole to reflect a regional (larger than the pluton) strain field and suggest that the "orogeny" recorded in and around the Sandia pluton involved a three dimensional strain field with subhorizontal extension (N-S) and contraction (E-W) directions. N-S extension is documented by the orientation of mineral lineations and movement directions in the basal shear zone and in high-strain zones in the northern aureole and by the orientations of tabular pegmatite and aplite dikes in the pluton and aureole. East to SE shortening is documented in the northern aureole by orientations of folded pegmatite dikes and associated S3 crenulation cleavage, and

  3. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy. PMID:26404834

  4. The microstructural effects of aqueous extract of Garcinia kola (Linn) on the hippocampus and cerebellum of malnourished mice

    PubMed Central

    Ajayi, Sunday A; Ofusori, David A; Ojo, Gideon B; Ayoka, Oladele A; Abayomi, Taiwo A; Tijani, Adekilekun A

    2011-01-01

    Objective To assess the neuroprotective effects of aqueous extract of Garcinia kola on neurotoxin administered malnourished mice adopting histological procedure. Methods The study was carried out using thirty-two adult malnourished mice which were randomly assigned into four groups (n=8): A, B, C and D. Group A served as control, while the other groups served as the experimental groups. Animals in group A were fed malnourished diet ad libitum and given water liberally. Animals in group B were administered with 3-Nitropropionic acid (3-NP) (neurotoxin) only at 20 mg/kg body weight, group C were given only Garcinia kola extracts, and group D were pre-treated with Garcinia kola extracts at 200 mg/kg for seven days prior to administration of neurotoxin at 20 mg/kg body weight. After three days of neurotoxins administration in the relevant groups, the brains were excised and fixed in formal calcium for histological processing. Results The study showed that hippocampal and cerebellar neurons of animals in group B exhibited some cellular degeneration and blood vessel blockage, which were not seen in groups A, C and D. Cresyl violet staining was least intense in group B than in groups A, C and D. Despite the fact that animals in group D has equal administration of 3-Nitropropionic acid concentration, there were no traces of neural degeneration as it was evidenced in group B. Conclusions It is concluded that Garcinia kola has protective effects on the neurons of the hippocampus and cerebellum of malnourished mice. PMID:23569771

  5. Paleoclimate and Paleoenvironmental Reconstructions on the North Kola Peninsula during the Past 2000 Years According Pollen Data

    NASA Astrophysics Data System (ADS)

    Nosevich, Ekaterina; Sapelko, Tatjana; Anisimov, Mikhail

    2014-05-01

    Pollen data and radiocarbon data have enabled to reconstruct the periods of vegetation that depended on the climate changes. Records from different types of deposits allow to receive more information and to make paleoclimate reconstructions. Lake and bog sediments are the best sources for palaeoreconstruction. Palaeoclimatic changes, tectonic and coastline movement during Late Holocene caused vegetation changes on the North Kola Peninsula. Our data from pollen records from different sites on the north coast of the Kola Peninsula covers the Late Holocene about last 2000 years. We studied different types of sediment cores in the area between 69° N and 70° N, 31°12' E and 35° E. We have studied peat deposits, small lake sediments and archaeological site on the Bolshoy Oleniy Island in Kola fjord, Barents Sea, and peat bog deposits in the Teriberka area. All the cores are studied by different methods where the core was pollen analysis. It has allowed tracking the periods of vegetation history in the tundra zone. Pollen reconstructions are confirmed by radiocarbon data. Our data was compared with other researches and we made correlations between pollen records from different lake deposits. Modern vegetation presents south tundra type of associations. Teriberka area is unique: almost existing types of tundra landscapes are presented here in small territory, including "typical tundra" with subshrubs formations. For paleoclimate reconstructions we have studied surface samples by pollen analysis. Samples were collected in 3 regions of Kola Peninsula. Samples have been taken on the Sredniy and Rybachiy Peninsulas (Murman region) in the south tundra with rich associations and boreal species of herbs. In the Olenegorsk region we selected vegetation associations not damaged by human and we collected surface samples on the border of forest tundra and northern taiga. In Apatity region we studied pollen records in North taiga landscapes. This data characterize regional and

  6. Volcanic-plutonic parity and the differentiation of the continental crust.

    PubMed

    Keller, C Brenhin; Schoene, Blair; Barboni, Melanie; Samperton, Kyle M; Husson, Jon M

    2015-07-16

    The continental crust is central to the biological and geological history of Earth. However, crustal heterogeneity has prevented a thorough geochemical comparison of its primary igneous building blocks-volcanic and plutonic rocks-and the processes by which they differentiate to felsic compositions. Our analysis of a comprehensive global data set of volcanic and plutonic whole-rock geochemistry shows that differentiation trends from primitive basaltic to felsic compositions for volcanic versus plutonic samples are generally indistinguishable in subduction-zone settings, but are divergent in continental rifts. Offsets in major- and trace-element differentiation patterns in rift settings suggest higher water content in plutonic magmas and reduced eruptibility of hydrous silicate magmas relative to dry rift volcanics. In both tectonic settings, our results indicate that fractional crystallization, rather than crustal melting, is predominantly responsible for the production of intermediate and felsic magmas, emphasizing the role of mafic cumulates as a residue of crustal differentiation. PMID:26178961

  7. Iron variation within a granitic pluton as determined by near-infrared reflectance

    NASA Technical Reports Server (NTRS)

    Baird, A. K.

    1984-01-01

    One-hundred fifty-one previously chemically analyzed samples of tonalite from the Lakeview Mountains pluton, southern California batholith, were analyzed for their iron content using near-infrared spectrophotometry. Compared to the earlier analyses of the same sample set by X-ray fluorescence spectrography, the infrared data have higher analytical variance but clearly define patterns of compositional zonation in the pluton which are closely similar to those patterns obtained from X-ray data; petrogenetic interpretations for the pluton would be the same from either data set. Infrared spectral data can be obtained directly in the field with relatively simple instruments and field measurements can be made to average local heterogeneities that often mask significant plutonic variations.

  8. Near-roof structure and crack-seal emplacement, Colosseum pluton, Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Bartley, J. M.; Glazner, A. F.; Coleman, D. S.

    2011-12-01

    Field evidence from diverse localities indicates that dike-like granitic plutons are emplaced by magmatic crack-seal, yielding plutons that are essentially huge composite dikes. Plutons that are equant in map view may also form by crack-seal from increments that are subhorizontal and vertically stacked, but field evidence to assess this hypothesis is scarce. Here we present evidence that the Late Cretaceous, granitic Colosseum pluton of Moore (1963), which crops out along the Sierra Nevada crest southwest of Big Pine, California, may have been emplaced as horizontal sheets by crack-seal. The equant outcrop pattern of the elliptical, 2x3 km Colosseum pluton as mapped by Moore (1963) mainly reflects Pleistocene glacial erosion that cut ~600 m down through the pluton's gently sloping roof contact. Moore mapped a steep eastern contact with the Spook pluton, but our field observations suggest that the Spook and Colosseum plutons may be the same. This would imply that the pluton is much larger and that the map pattern is not elliptical. Additionally, the exposed intrusive contact everywhere dips gently, but the eastern intrusive contact has been cut off by the Sierran frontal fault. If so, up to 2.5 km of largely unexplored vertical relief in the pluton is exposed on the eastern escarpment of the Sierra Nevada. Geologic and bulk magnetic susceptibility mapping of near-roof rocks revealed the following. (1) Although the intrusive contact sharply truncates wall-rock foliation, xenoliths are absent, even at contacts, indicating that stoping was an insignificant process. (2) The pluton contains a subhorizontal sheet of leucogranite that is broadly concordant with the roof but bounded both above and below by more typical biotite granodiorite. This sheet may represent one or more intrusive increments. (3) Along the western contact, thin tabular apophyses of the pluton intrude its subvertically layered and foliated roof. Although some of these dip steeply and are concordant

  9. Ulvöspinel from xenoliths of contact-altered volcanic and volcanosedimentary rocks in nepheline syenites of the Khibiny and Lovozero plutons

    NASA Astrophysics Data System (ADS)

    Ivanyuk, G. Yu.; Korchak, Yu. A.; Pakhomovsky, Ya. A.; Men'shikov, Yu. P.; Yakovenchuk, V. N.

    2012-12-01

    Ulvöspinel is a typical accessory mineral of xenoliths of volcanic and volcanosedimentary rocks in alkaline syenites of the Khibiny and Lovozero plutons. Ulvöspinel forms homogeneous Cr- and V-rich grains in slightly altered olivine basalts, basaltic tuffs, and tuffites and is enriched in Mn and Si in the course of contact-metasomatic alteration of these rocks. The strongly reduced conditions of contact metamorphism controlled by ascending flows of hydrocarbon gases and hydrogen sulfide gave rise to the subsolidus decomposition of primary ulvöspinel and Ti-high magnetite with the formation of ilmenite lamellae and then, with decreasing redox potential, of the second-generation latticed ulvöspinel lamellae.

  10. Cyclicity of forest fire occurrence at Kola Peninsula (North-Western Russia) in connection to meteorological and solar activity

    NASA Astrophysics Data System (ADS)

    Shumilov, O. I.; Kasatkina, E. A.; Knyazev, N. V.; Lukina, N. V.

    2010-05-01

    The cyclicity of forest fire number for the period 1958-2007 at Kola Peninsula was investigated. We used the data of regular aerial surveying. The frequency of forest fires was compared with regional meteorological and dendrochronological records. Spectral analysis with help of MEM and wavelet revealed a clear cyclic character of fire occurrence with two main maxima. The main one occurred at frequencies around 18-20 years and the other in the band 2.8-4 year. Detailed analysis showed that fire occurrence at Kola Peninsula was a result of a complicated mixture of both anthropogenic and climatic forcings (temperature and precipitation). Climatic forcing is influenced by variations of solar activity (solar radiation, cosmic rays, cosmic dust etc.). Two maxima in the fire occurrence spectrum seem to be connected to one of the main cycles of solar activity (22 y) and NAO oscillation (3-4 y). As it is well known the NAO variations are rather tightly connected to cyclonic activity in the North Atlantic region. The enhanced numbers of fires were observed close to minima of solar activity. These results may be applied for fire forecasting at Kola Peninsula. This work is financially supported by the Russian Foundation for Basic Research (grant No. 09-04-98801), by the Program of the Russian Academy and by the Regional Scientific Program of Murmansk region.

  11. Nutrient and phytochemical composition of two varieties of Monkey kola (Cola parchycarpa and Cola lepidota): An underutilised fruit.

    PubMed

    Ene-Obong, Henrietta N; Okudu, Helen O; Asumugha, Ukamaka V

    2016-02-15

    The nutrient and phytochemical composition of two varieties of Monkey kola: Cola parchycarpa and Cola lepidota were determined. The pulps were extracted, grated and dried using solar dryer. Dried pulps were milled into flour with attrition milling machine (0.5mm sieve size). The nutrient compositions were determined using standard AOAC methods. Gravimetric and spectrophotometric methods were used for phytochemical determinations. There were significant (p<0.05) differences in the proximate and some mineral and vitamin composition of the two varieties. Most abundant minerals were calcium (195-199mg for C. parchycarpa), potassium (204-209mg/100g for C. lepidota) and β-carotene (2755-5028μg/100g for C. parchycarpa). Calcium:phosphorus and sodium:potassium ratios were adequate (>1.0 and ⩽0.06, respectively). Monkey kola had substantial amounts of iron, zinc, and copper; the B-vitamins and vitamin C. The phytochemical contents were quiet high, the most abundant being flavonoids (415-494mg/100g). Monkey kola is a fruit that should be fully exploited for its potential health benefits. PMID:26433302

  12. Petrology and Geochemistry of Neoproterozoic Arc Plutons Beneath the Atlantic Coastal Plain, SRS, SC

    SciTech Connect

    Maryak, M.

    1998-10-21

    In this report is presented first a brief review of the regional geologic setting of the Savannah River Site, descriptions of the plutonic rock units sampled here, whole rock geochemical data on the plutonic igneous rocks, and finally, a discussion of how the crystalline basement rocks of the Savannah River Site formed and how they may correlate with other terranes exposed in the Piedmont of the Carolinas, Georgia, and Virginia.

  13. Tertiary epizonal plutonic rocks of the Selway-Bitterroot Wilderness, Idaho County, Idaho

    SciTech Connect

    Motzer, W.E.

    1996-01-01

    Geologic mapping in the Selway-Bitterroot Wilderness identified approximately 731 kmS of epizonal plutonic granitic rocks within the Bitterroot lobe of the Idaho batholith. From north to south, the intrusions are the Rock Lake Creek stock and the Whistling Pig, Running Creek, Bad Luck and Painted Rocks plutons. The stock and plutons consist of medium- to coarse-grained biotite and hornblende-biotite syenorgranite to monzogranite and quartz syenite capped by fine-grained biotite leucogranite. These rocks are intruded by late-synplutonic leucogranite dikes and post plutonic porphyritic rhyolite to rhyodacite and basalt dikes. The medium-grained granitic rocks are high in SiO2, K2O, Na2O, Ga, Th, U, W and Zr, but low in Al7O3, CaO, MgO, Cr, Ni, Co and V. Most of the granites are peraluminous. Rare-earth element (REE) plots (rock sample/chondrite) show enrichment in light REE over heavy REE with strong EU depletions. K-Ar biotite radiometric age determinations for medium-grained granites in all of the plutons range from approximately 51 Ma (Whistling Pig pluton) to 43.7 Ma (Painted Rocks pluton). Petrogenetic studies suggest that the plutons were rapidly emplaced to within 3.0 km of the paleosurface. The types, textures and color of the rocks result from devolatilization of the crystallizing melt and very low-grade hydrothermal alteration. The fluorine-rich melts are the fractionated with accumulate residue; they are considered to be anorogenic (A-type) granites intruded into the center of a metamorphic core complex.

  14. The northern coast plutonic-metamorphic complex, southeastern Alaska and northwestern British Columbia

    NASA Astrophysics Data System (ADS)

    Brew, D. A.; Ford, A. B.

    The northern Coast plutonic-metamorphic complex is but one segment of an 8,000-km-long batholithic complex that extends the length of the North American Cordillera from Baja, California to the Aleutian Islands. Different segments of the Cordilleran batholithic complex have significantly different features. This report documents the main characteristics and inferred evolutionary history of the northern Coast plutonic-metamorphic complex that should facilitate comparisons between segments.

  15. Uranium-Lead Zircon Ages and Sr, Nd, and Pb Isotope Geochemistry of Selected Plutonic Rocks from Western Idaho

    USGS Publications Warehouse

    Unruh, Daniel M.; Lund, Karen; Kuntz, Mel A.; Snee, Lawrence W.

    2008-01-01

    Across the Salmon River suture in western Idaho, where allochthonous Permian to Cretaceous oceanic rocks are juxtaposed against Proterozoic North American rocks, a wide variety of plutonic rocks are exposed. Available data indicate much variation in composition, source, and structural state of these plutons. The plutonic rocks were long described as the western border zone of the Cretaceous Idaho batholith but limited pre-existing age data indicate more complicated origins. Because the affinity and age of the plutonic rocks cannot be reliably determined from field relations, TIMS U-Pb dating in conjunction with Sr, Nd, and Pb isotopic studies of selected plutons across the suture in western Idaho were undertaken. The data indicate three general groups of plutons including (1) those that intruded the island arc terranes during the Triassic and Jurassic, those that intruded near the western edge of oceanic rocks along the suture in the Early Cretaceous, and the plutons of the Idaho batholith that intruded Proterozoic North American rocks in the Late Cretaceous. Plutons that intruded Proterozoic North American rocks commonly include xenocrystic zircons and in several cases, ages could not be determined. The least radiogenic Sr and most radiogenic Nd are found among the Blue Mountains superterrane island arc samples. Suture-zone plutons have isotopic characteristics that span the range between Idaho batholith and island arc samples but mostly follow island arc signatures. Plutons of the Idaho batholith have the most radiogenic initial Pb and Sr ratios and the least radiogenic Nd of the samples analyzed.

  16. Symmagmatic folding of the base of the Bergell pluton, Central Alps

    NASA Astrophysics Data System (ADS)

    Davidson, C.; Rosenberg, C.; Schmid, S. M.

    1996-11-01

    Evidence for magmatic, submagmatic and solid-state deformation in tonalite, granodiorite and country rocks found at the deep-seated floor (22-26 km) of the Bergell pluton demonstrates that final emplacement and crystallization occurred during regional deformation of the pluton and the underlying country rocks. After northward emplacement over the country rocks, but before complete crystallization, the floor of the pluton was folded during simultaneous N-S shortening and E-W stretching. This is evidenced by synmagmatic folds with E-W striking, nearly vertical axial planes, and by regional east-plunging stretching lineations in the country rocks which are parallel to the regional-scale fold axes and the magmatic mineral lineations in the pluton. Opposite senses of shear from the well-foliated, occasionally mylonitic contact suggest that deformation was mostly accomplished by pure shear. Synmagmatic deformation is related to late-stage N-S shortening of the Alpine orogen and shows that the still partially molten pluton responded to low differential stress very much like the country rocks deformed in the solid-state at high temperatures. Post-emplacement tilting associated with backthrusting along the Insubric mylonites led to the exposure of the pluton's floor at its present-day western margin.

  17. Origin of mineralogical zoning in an intermediate subvolcanic pluton by crystal settling and conductive cooling

    SciTech Connect

    Hildebrand, R.S.

    1985-01-01

    The Rainy Lake Intrusive Complex is one of nine sheet-like intermediate plutons that are compositionally, temporally, and spatially linked to andesitic stratovolcanoes in the western Great Bear Magmatic Zone, an early Proterozoic continental magmatic arc. The pluton, exposed in oblique cross section, has a flat roof and is 1.5 km thick by 12 km long. The observed distribution of plagioclase phenocrysts in the body closely resembles the sinusoidal olivine distribution patterns found in lava lakes and some mafic sills. The shape of the curve indicates that the volume fraction plagioclase phenocrysts in the pluton at the time of intrusion ranged for 10% near the roof to 50% near the base. Calculations indicate that the plagioclase phenocrysts were denser than the surrounding melt. The effects of different crystal concentrations on the viscosity, and hence settling velocities, were computed as a function of height in the pluton; settling velocities ranged, at the time of intrusion, from 160 meters per year near the top to less than 1 meter per year near the base. The observed sinusoidal distribution curve for plagioclase can be explained by the interplay between crystal settling and the solidification of the pluton from the top downwards and the bottom upwards. This suggests that whole body convection did not play a major role in the cooling of the pluton.

  18. Petrogenetic evolution of the Early Miocene Alaçamdağ volcano-plutonic complex, northwestern Turkey: implications for the geodynamic framework of the Aegean region

    NASA Astrophysics Data System (ADS)

    Erkül, Sibel Tatar

    2012-01-01

    Extensional-tectonic processes have generated extensive magmatic activity that produced volcanic/plutonic rocks along an E-W-trending belt across north-western Turkey; this belt includes granites and coeval volcanic rocks of the Alaçamdağ volcano-plutonic complex. The petrogenesis of the Early Miocene Alaçamdağ granitic and volcanic rocks are here investigated by means of whole-rock Sr-Nd isotopic data along with field, petrographic and whole-rock geochemical studies. Geological and geochemical data indicate two distinct granite facies having similar mineral assemblages, their major distinguishing characteristic being the presence or absence of porphyritic texture as defined by K-feldspar megacrysts. I-type Alaçamdağ granitic stocks have monzogranitic-granodioritic compositions and contain a number of mafic microgranular enclaves of monzonitic, monzodioritic/monzogabbroic composition. Volcanic rocks occur as intrusions, domes, lava flows, dykes and volcanogenic sedimentary rocks having (first episode) andesitic and dacitic-trachyandesitic, and (second episode) dacitic, rhyolitic and trachytic-trachydacitic compositions. These granitic and volcanic rocks are metaluminous, high-K, and calc-alkaline in character. Chondrite-normalised rare earth element patterns vary only slightly such that all of the igneous rocks of the Alaçamdağ have similar REE patterns. Primitive-mantle-normalised multi-element diagrams show that these granitic and volcanic rocks are strongly enriched in LILE and LREE pattern, high (87Sr/86Sr)i and low ɛ Nd( t) ratios suggesting Alaçamdağ volcano-plutonic rocks to have been derived from hybrid magma that originated mixing of co-eval lower crustal-derived more felsic magma and enriched subcontinental lithospheric mantle-derived more mafic magmas during extensional processes, and the crustal material was more dominant than the mantle contribution. The Alaçamdağ volcano-plutonic complex rocks may form by retreat of the Hellenic

  19. Alkaline Phosphatase in Stem Cells

    PubMed Central

    Štefková, Kateřina; Procházková, Jiřina; Pacherník, Jiří

    2015-01-01

    Alkaline phosphatase is an enzyme commonly expressed in almost all living organisms. In humans and other mammals, determinations of the expression and activity of alkaline phosphatase have frequently been used for cell determination in developmental studies and/or within clinical trials. Alkaline phosphatase also seems to be one of the key markers in the identification of pluripotent embryonic stem as well as related cells. However, alkaline phosphatases exist in some isoenzymes and isoforms, which have tissue specific expressions and functions. Here, the role of alkaline phosphatase as a stem cell marker is discussed in detail. First, we briefly summarize contemporary knowledge of mammalian alkaline phosphatases in general. Second, we focus on the known facts of its role in and potential significance for the identification of stem cells. PMID:25767512

  20. Geochemical characteristics of the Bulgarmarse Granite of the Fall River Pluton in the Avalonian Superterrane of southeastern New England

    SciTech Connect

    Mancuso, C.I.; Puffer, J.H. . Dept. of Geological Sciences)

    1993-03-01

    The 600 m.y. Bulgarmarsh Granite of the Fall River Pluton crops out along the SE margin of the Pennsylvanian-age Narragansett Basin in the Dedham terrane of the New England Avalonian Superterrane. The Bulgarmarsh is a coarse-grained, quartz-rich, very leucooratic granite, in which mafic minerals, generally less than 5--8%, occur chiefly as chlorite, biotite and garnet disequilibrium intergrowths. Most of the granite is very slightly deformed, but there are many localized zones of deformation, both brittle and plastic, that vary in degree of intensity. The Bulgarmarsh intrudes Basin margin metavolcanics similar to those of Price Neck Formation that crop out within the Basin in Newport and on Gould Island. The Bulgarmarsh Granite has many of the mineralogical and geochemical characteristics of an A-type granite. Its geochemistry places it in the post-orogenic classification of Maniar and Piccoli (1989). New major and minor element geochemical data clearly discriminate between the Bulgarmarsh Granite and the adjacent calc-alkaline Metacom Granite Gneiss. Avalonian Orogeny, occupying a place in geologic history similar to that of the Newport Granite.

  1. Archean to Paleoproterozoic polymetamorphic history of the Salma eclogite in Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Imayama, Takeshi; Oh, Chang-Whan; Park, Chan-Soo; Yi, Keewook; Jung, Haemyeong

    2015-04-01

    One of the most important questions in the Earth Science is when and how plate tectonics operate in the Precambrian time. The tectonic and thermal evolution of the Precambrian eclogite is significant key for understanding the Precambrian geodynamic mechanisms. Eclogites in Kola Peninsula, Russia are some of the oldest eclogites of the world, but there has been much debate about the timing of eclogite-facies metamorphism: Archean (e.g. Volodichev et al. 2004; Mints et al., 2010) or Paleoproterozoic (e.g. Skublob et al., 2011, 2012). The controversy is mainly because of the lack of zircon dating coupled with the formation of garnet and omphacite. In this study, we present geochronological, petrographic, and geochemical data from the Salma eclogites in the Kola Peninsula, Russia to characterize subduction and collision processes in the Precambrian. Microstructural observations, P-T analyses, zircon inclusion analyses, and U-Pb zircon dating revealed multiple metamorphic stages that the Salma eclogite underwent. The amphibolite facies metamorphic event firstly occurred at 2.73-2.72 Ga during Archean. In the Paleoproterozoic period, the Salma eclogites underwent prograde stage of epidote-amphibolite facies metamorphism. The eclogite facies metamorphic event took place under the P-T condition of 16-18 kbar and 740-770 °C at 1.89-1.88 Ga, with a subsequent granulite facies metamorphism during decompression stage from 18 kbar to 9-12 kbar. Finally, later amphibolite facies metamorphism occurred at 8-10 kbar and 590-610 °C on cooling. The Archean metamorphic zircons that contain inclusions of Grt + Am + Bt + Pl + Qtz + Rt are unzoned grains with dark CL, and they are relatively enriched in HREE. In contrast, the 1.89-1.88 Ga sector or concentric zoned zircons with pale-grey CL include inclusions of Grt + Omp + Ca-Cpx + Am + Bt + Qtz + Rt, and they have the flat pattern of HREE due to the amounts of abundant garnet during the eclogite-facies metamorphism. Whole rock

  2. Isotopic constraints on the petrogenesis of jurassic plutons, Southeastern California

    USGS Publications Warehouse

    Mayo, D.P.; Anderson, J.L.; Wooden, J.L.

    1998-01-01

    The 165 Ma Eagle Mountain intrusion is a heterogeneous, enclave-bearing, metaluminous remnant of the Cordilleran Jurassic arc that cuts regionally metamorphosed pre-Mesozoic rocks in the southeastern Mojave Desert of California. The main phase of the intrusion consists of granodiorite to tonalite host facies, diorite mixed facies, and homogeneous monzogranite facies. The host facies contains microdiorite enclaves interpreted as intermingled masses of mafic magma. Late-phase leucogranite stocks cut the main phase. Mineral equilibria indicate emplacement at ???6.5 km depth, with solidus temperatures ranging from 760??C for diorite to 700??C for felsic granodiorite. Although uniform radiogenic-isotope compositions (Sri = 0.7085, ???Ndi = -9.4) suggest derivation from a single source, no known source has the composition required. A hybrid source is proposed, consisting of various proportions of juvenile mantle and recycled lower crust. Calculations indicate that the source of the Eagle Mountain intrusion comprised >60% juvenile mantle and <40% recycled crust. On the basis of their isotopic compositions, other mafic Jurassic plutons in the region were derived from sources containing different proportions of mantle and crustal components.

  3. Alkaline fuel cells applications

    NASA Astrophysics Data System (ADS)

    Kordesch, Karl; Hacker, Viktor; Gsellmann, Josef; Cifrain, Martin; Faleschini, Gottfried; Enzinger, Peter; Fankhauser, Robert; Ortner, Markus; Muhr, Michael; Aronson, Robert R.

    On the world-wide automobile market technical developments are increasingly determined by the dramatic restriction on emissions as well as the regimentation of fuel consumption by legislation. Therefore there is an increasing chance of a completely new technology breakthrough if it offers new opportunities, meeting the requirements of resource preservation and emission restrictions. Fuel cell technology offers the possibility to excel in today's motive power techniques in terms of environmental compatibility, consumer's profit, costs of maintenance and efficiency. The key question is economy. This will be decided by the costs of fuel cell systems if they are to be used as power generators for future electric vehicles. The alkaline hydrogen-air fuel cell system with circulating KOH electrolyte and low-cost catalysed carbon electrodes could be a promising alternative. Based on the experiences of Kordesch [K. Kordesch, Brennstoffbatterien, Springer, Wien, 1984, ISBN 3-387-81819-7; K. Kordesch, City car with H 2-air fuel cell and lead-battery, SAE Paper No. 719015, 6th IECEC, 1971], who operated a city car hybrid vehicle on public roads for 3 years in the early 1970s, improved air electrodes plus new variations of the bipolar stack assembly developed in Graz are investigated. Primary fuel choice will be a major issue until such time as cost-effective, on-board hydrogen storage is developed. Ammonia is an interesting option. The whole system, ammonia dissociator plus alkaline fuel cell (AFC), is characterised by a simple design and high efficiency.

  4. Geochemistry, geochronology and zircon Hf isotopic study of peralkaline-alkaline intrusions along the northern margin of the North China Craton and its tectonic implication for the southeastern Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    Zhao, Pan; Jahn, Bor-ming; Xu, Bei; Liao, Wen; Wang, Yanyang

    2016-09-01

    A giant Permian alkaline magmatic belt has recently been identified in southern Inner Mongolia, along the northern margin of the North China Craton (NCC). This belt is mainly composed of syenite, quartz syenite, alkaline granite and mafic microgranular enclaves (MME)-bearing granodiorite. In order to study the petrogenesis and tectonic implications of these rocks, we undertook zircon U-Pb dating and geochemical analysis of two Permian alkaline plutons. The first Guangxingyuan Pluton occurs in the Hexigten area and is composed of MME-bearing tonalite, K-feldspar granite and syenite. The second Durenwuliji Pluton, located in the Xianghuangqi area, comprises syenite, quartz syenite and K-feldspar granite. Zircon U-Pb dating on tonalite, K-feldspar granite, syenite and quartz syenite from the two plutons yielded a tight range of ages from 259 to 267 Ma. The peralkaline-alkaline rocks show high abundance of total alkalis (K2O + Na2O = 7.9-12.9%) and K2O contents (3.9-8.0%), enrichment in large ion lithophile elements (LILE) and light rare earth element (LREE), and depletion of high field strength elements (HFSE). The associated tonalite and MMEs display I-type granitic geochemical affinity, with less total abundance of trace elements than the peralkaline-alkaline rocks. Zircon Hf isotopic analysis of the Guangxingyuan pluton yielded a large range of εHf(t) values from - 15.5 to + 6.7 and model ages (TDMC) from 781 to 2012 Ma. By contrast, the Hf isotopic data of the Durenwuliji pluton shows a small range of εHf(t) from + 6.2 to + 8.9 and TDMC from 667 to 816 Ma. The geochemical and Hf isotopic characteristics indicate that the parental magma was derived from a mixing of metasomatic mantle-derived mafic magma with different amount of crust-derived felsic magma, and followed by fractional crystallization. Considering previous tectonic studies in Inner Mongolia, a Permian post-orogenic extension was proposed to account for these peralkaline-alkaline intrusions following

  5. Dose- and time-dependent effects of Garcinia kola seed extract on sexual behaviour and reproductive parameters in male Wistar rats.

    PubMed

    Sewani-Rusike, C R; Ralebona, N; Nkeh-Chungag, B N

    2016-04-01

    The aim of the present study was to investigate the effects of a crude extract of Garcinia kola on male sexual function after subchronic and chronic treatment periods at different sublethal doses. Adult male Wistar rats were treated orally with 100, 200 and 400 mg kg(-1) of a 70% ethanolic extract of G. kola daily for 56 days. Sexual behaviour studies were performed on days 28 and 50. At termination on day 56, organ weights, sperm count, reproductive hormone levels and testicular histology were assessed. Subchronic and chronic treatment of normal male rats with G. kola extract resulted in overall increase in components of libido, erection and ejaculation in treated rats - with lower doses being more efficient than the higher dose. There was a slight reduction in some components of sexual behaviour with prolonged time of treatment. G. kola treatment at all doses resulted in increased testicular weights, increased sperm count with no change in motility and increased serum testosterone levels with no change in gonadotropin levels. Gross testicular histology was not affected by treatment. We conclude that G. kola seed extract possesses potent aphrodisiac activity in male albino rats with resultant increase in sperm count and testosterone levels. PMID:26123866

  6. Constraints on the depth of generation and emplacement of a magmatic epidote-bearing quartz diorite pluton in the Coast Plutonic Complex, British Columbia

    USGS Publications Warehouse

    Chang, J.M.; Andronicos, C.L.

    2009-01-01

    Petrology and P-T estimates indicate that a magmatic epidote-bearing quartz diorite pluton from Mt. Gamsby, Coast Plutonic Complex, British Columbia, was sourced at pressures below ???1.4 GPa and cooled nearly isobarically at ???0.9 GPa. The P-T path indicates that the magma was within the stability field of magmatic epidote early and remained there upon final crystallization. The pluton formed and crystallized at depths greater than ???30 km. REE data indicate that garnet was absent in the melting region and did not fractionate during crystallization. This suggests that the crust was less than or equal to ???55 km thick at 188 Ma during the early phases of magmatism in the Coast Plutonic Complex. Late Cretaceous contractional deformation and early Tertiary extension exhumed the rocks to upper crustal levels. Textures of magmatic epidote and other magmatic phases, combined with REE data, can be important for constraining the P-T path followed by magmas. ?? 2009 Blackwell Publishing Ltd.

  7. Is there a geochemical link between volcanic and plutonic rocks in the Organ Mountains caldera?

    NASA Astrophysics Data System (ADS)

    Memeti, V.; Davidson, J.

    2013-12-01

    Results from separate volcanic and plutonic studies have led to inconsistent conclusions regarding the origins and thus links between volcanic and plutonic systems in continental arcs and the magmatic processes and time scales responsible for their compositional variations. Some have suggested that there is a geochemical and geochronological disconnect between volcanic and plutonic rocks and hence have questioned the existence of magma mush columns beneath active volcanoes. Investigating contemporary volcanic and plutonic rocks that are spatially connected is thus critical in exploring these issues. The ca. 36 Ma Organ Mountains caldera in New Mexico, USA, represents such a system exposing contemporaneous volcanic and plutonic rocks juxtaposed at the surface due to tilting during extensional tectonics along the Rio Grande Rift. Detailed geologic and structural mapping [1] and 40Ar/39Ar ages of both volcanics and plutons [2] demonstrate the spatial and temporal connection of both rock types with active magmatism over >2.5 myr. Three caldera-forming ignimbrites erupted within 600 kyr [2] from this system with a total erupted volume of 500-1,000 km3 as well as less voluminous pre- and post-caldera trachyte and andesite lavas. The ignimbrite sequence ranges from a crystal-poor, high-SiO2 rhyolite at the base to a more crystal-rich, low-SiO2 rhyolite at the top. Compositional zoning with quartz-monzonite at the base grading to syenite and alaskite at the top is also found in the Organ Needle pluton, the main intrusion, which is interpreted to be the source for the ignimbrites [1]. Other contemporaneous and slightly younger plutons have dioritic to leucogranitic compositions. We examined both volcanic and plutonic rocks with petrography and their textural variations with color cathodoluminescence, and used whole rock element and Sr, Nd and Pb isotope geochemistry to constrain magma compositions and origins. Electron microprobe analyses on feldspars have been completed to

  8. Mineral potential of selected felsic plutons in the eastern and southeastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    du Bray, Edward A.

    1983-01-01

    Most of the plutons studied are similar to metallogenically specialized granites described elsewhere in the world and found associated with deposits of tin, tungsten, or molybdenum and other rare metals. Only four of the plutons, the Sitarah, Tarban, and Gaharra monzogranites and the Bwana granite, contained highly anomalous amounts of tin, tungsten, or molybdenum and altered zones- and (or) numerous quartz veins and otherwise appeared to have noteworthy mineral potential. Additional work on at least these four plutons is suggested.

  9. Calc-alkaline rear-arc magmatism in the Fuegian Andes: Implications for the mid-cretaceous tectonomagmatic evolution of southernmost South America

    NASA Astrophysics Data System (ADS)

    Guillot, Mauricio González; Escayola, Mónica; Acevedo, Rogelio

    2011-02-01

    The magmatic arc of the Fuegian Andes is composed mostly of Upper Mesozoic to Cenozoic calc-alkaline plutons and subordinated lavas. To the rear arc, however, isolated mid-Cretaceous monzonitic plutons and small calc-alkaline dykes and sills crop out. This calc-alkaline unit (the Ushuaia Peninsula Andesites, UPA) includes hornblende-rich, porphyritic quartz meladiorites, granodiorites, andesites, dacites and lamprophyres. Radiometric dating and cross-cutting relationships indicate that UPA is younger than the monzonitic suite. The geochemistry of UPA is medium to high K, with high LILE (Ba 500-2000 ppm, Sr 800-1400 ppm), HFSE (Th 7-23 ppm, Nb 7-13 ppm, Ta 0.5-1.1 ppm) and LREE (La 16-51 ppm) contents, along with relatively low HREE (Yb 1.7-1.3 ppm) and Y (9-19 ppm). The similar mineralogy and geochemistry of all UPA rocks suggest they evolved from a common parental magma, by low pressure crystal fractionation, without significant crustal assimilation. A pure Rayleigh fractionation model indicates that 60-65% of crystal fractionation of 60% hornblende + 34% plagioclase + 4% clinopyroxene + 1% Fe-Ti oxide, apatite and sphene (a paragenesis similar of UPA mafic rocks) can explain evolution from lamprophyres to dacites. The UPA has higher LILE, HFSE and LREE, and lower HREE and Y than the calc-alkaline plutons and lavas of the volcanic front. The HREE and Y are lower than in the potassic plutons as well. High concentrations of Th, Nb, Ta, Zr, Hf, LREE and Ce/Pb, and low U/Th, Ba/Th ratios in UPA, even in the least differentiated samples, suggest contributions from subducted sediments to the mantle source. On the other hand, relatively low HREE and Y, high LREE/HREE (La/Yb 11-38) ratios and Nb-Ta contents can be interpreted as mantle metasomatism by partial melts of either subducted garnetiferous oceanic sediment or basalt as well. Additionally, high LILE content in UPA, similar to the potassic plutons, suggests also a mantle wedge previously metasomatized by potassic

  10. 4-Dimensional Insights into Silicic Magma Reservoir Assembly from Late Miocene Southern Andean Plutons

    NASA Astrophysics Data System (ADS)

    Schaen, A. J.; Garibaldi, N.; Singer, B. S.; Schoene, B.; Cottle, J. M.; Tikoff, B.; Gutiérrez, F. J.; Jicha, B. R.; Payacán, I. J.

    2015-12-01

    Linking the development of magmatic flow fabrics to the T-X-t history of intraplutonic domains using modern structural and petrochronologic methods offers a frontier along which to explore for eruptability in plutonic rocks and better understand how shallow magma systems are assembled. The ~6.2 Ma Risco Bayo and Huemul plutons in the Chilean Andes (~36°S) exhibit a similar compositional spectrum and footprint to the active Laguna del Maule rhyolitic volcanic field nearby. The plutons comprise distinct lithological domains-each on the order of a few km3: gabbro to granite in Risco Bayo and granodiorite to leucogranite in Huemul. Whole rock variations and 87Sr/86Sr ratios highlight the importance of AFC processes during pluton assembly. Mixing and mingling of magma batches is observed geochemically and in the field as abundant mafic enclaves. U-Pb CA-ID-TIMS zircon ages of 6.36 to 6.18 Ma in Risco Bayo granodiorite and Huemul miarolitic leucogranite overlap with their 40Ar/39Ar biotite ages of ~6.24 Ma, suggesting coeval zircon saturation, emplacement, and rapid cooling of two compositionally and structurally distinct domains. A granodiorite domain within Huemul has a more protracted crystallization history and zircons with lower REE than in the adjacent miarolitic leucogranite, suggesting pluton construction by pulses on 10 to 100 kyr timescales. Al-in-hornblende barometry constrains emplacement to 3-4 km depth. Observations from Laguna del Maule (extrusion/intrusion rates, spatio-temporal pattern of mafic/rhyolitic volcanism, etc.) provide volcanic parallels with which to help interpret pluton assembly. AMS fabrics suggest possible upward migration of magma associated with decompression. Late Miocene silicic ignimbrites nearby are also being investigated to determine if they represent erupted products from the Risco Bayo-Huemul plutonic system.

  11. Magnetic Fabrics and Their Relationship with the Emplacement of the Piracaia Pluton, se Brazil

    NASA Astrophysics Data System (ADS)

    Raposo, M. B.; Pressi, L. F.; Janasi, V. D.

    2010-12-01

    Magnetic fabric and rock magnetism studies were performed on the four units of the 578 +/- 3 Ma-old Piracaia pluton (NW of São Paulo State, southern Brazil). This intrusion is roughly elliptical (~ 32 km2), composed of (i) coarse-grained monzodiorite (MZD-c), (ii) fine-grained monzodiorite (MZD-f) which is predominant in the pluton, (iii) monzonite heterogeneous (MZN-het), and (iv) quartz syenite (Qz-Sy). Magnetic fabrics were determined by applying both anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). The two fabrics are coaxial. The parallelism between AMS and AARM tensors excludes the presence of a single domain (SD) effect on the AMS fabric of the units. Several rock-magnetism experiments performed in one specimen from each sampled unit show that for all units the magnetic susceptibility and magnetic fabrics are carried by magnetite grains. Foliations and lineations in the units were successful determined by applying magnetic methods. Most of the magnetic foliations are steeply dipping or vertical in all units, and are roughly parallel to the foliation measured in the field and in the rocks which surround the pluton. In contrast, the magnetic lineations present mostly low plunges for the whole pluton. However, for two sites they are steep. Thin section analysis show that rocks from the Piracaia pluton were affected by the regional strain during and after emplacement since magmatic foliation evolves to solid-state deformation in the north and south of the pluton, indicating clearly that magnetic fabrics are related to this strain. Otherwise, the lack of solid-state deformation at outcrop scale and in thin sections precludes deformation in the SW of the pluton. This evidence allows us to interpret the observed magnetic fabrics as primary in origin (magmatic) acquired when the rocks were solidified as a result of magma flow, in which steeply plunging magnetic lineation suggests that a feeder zone

  12. Silica in alkaline brines

    USGS Publications Warehouse

    Jones, B.F.; Rettig, S.L.; Eugster, H.P.

    1967-01-01

    Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO 2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied by a rise in pH. Supersaturation with respect to amorphous silica may occur and persist for brines that are out of contact with silicate muds and undersaturated with respect to trona; correlation of SiO2 with concentration of Na and total CO2 support this interpretation. Addition of moredilute waters to alkaline brines may lower the pH and cause inorganic precipitation of substantial amounts of silica.

  13. Bifunctional alkaline oxygen electrodes

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

  14. Gas chromatography-mass spectrometry characterisation of the anti-Listeria components of Garcinia kola seeds.

    PubMed

    Penduka, D; Basson, K A; Mayekiso, B; Buwa, L; Okoh, I A

    2014-01-01

    Adsorption chromatography was used to separate the bioactive constituents of the crude n-hexane extract of Garcinia kola seeds. The silica gel 60 column fractions were eluted using the solvent combination of benzene: ethanol : ammonium hydroxide (BEA) in the ratio combination of 36 : 4 : 0.4 v/v. The fractions were tested for anti-Listeria activities by determining their MIC50, MIC90 or MIC against 4 Listeria isolates. The fractions were labelled BEA1 to BEA5 and 3 out of the 5 fractions eluted were active against the test Listeria species with MIC's ranging from MIC 0.57 mg/mL to MIC50 0.625 mg/mL. The most active fractions, BEA2 and BEA3, were subjected to gas chromatography coupled to mass spectrometry (GC-MS) to identify their composition. Fraction BEA2 constituted of 18 compounds mostly sterols and the BEA3 fraction contained 27 compounds with the most abundant compounds being fatty acids derivatives. The BEA2 fraction's interactions with antibiotics proved to be 100% synergistic with ciprofloxacin and ampicillin whilst it exhibited 50% additivity and 50% synergism with penicillin G. However, all the interactions of the BEA2 fraction with each of the conventional antibiotics used were synergistic against the human listeriosis causative bacteria Listeria monocytogenes. PMID:25757343

  15. Heavy metals in surface lake sediments on the Kola Penninsula as an index of air quality

    SciTech Connect

    Dauvalter, V.

    1996-12-31

    The investigations of heavy metal (Ni, Cu, Co, Zn, Pb, Cd, Hg) distribution in sediments of more than 100 lakes were carried out between 1989 and 1994. The study lakes are situated at different distances from two main heavy metal pollution sources of the Kola Peninsula-smelters of the Pechenganickel and Severonickel Companies. To assess the pollution extent of investigated lakes, values of factor and degree of contamination were calculated according to the method suggested by Hakanson (1980). Heavy metal contamination factor (C{sub f}) for each heavy metal was calculated as the quotient of concentration from the uppermost (0-1 cm) sediment to the mean preindustrial background value (concentrations from 20-30 cm sediment layers) for the investigated region. Degree of contamination (C{sub d}) was defined as the sum of all contamination factors for studied heavy metals. To quantitatively express the potential ecological risk of given contaminants created for ecosystems, risk factor (Er) for each heavy metal has been calculated. Er takes into account the toxicity of a heavy metal and bioproduction index (BPI) of a lake. Risk index (RI) was determined as the sum of all ecological risk factor for studied heavy metals.

  16. Raman spectra of probably shock-metamorphosed zircon in structures of the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Kaulina, Tatiana; Nerovich, Luidmila; Lialina, Luidmila; Il'chenko, Vadim; Bocharov, Vladimir; Kunakkuzin, Evgeny

    2016-04-01

    Zircon crystals were studied by means of Raman spectroscopy from certain structures of the Kola Peninsula, for which impact events are expected according to geological and geochemical data: circular structure in Javrozersky area of the Tanaelv belt and granophyres of Jarva-Varaka layered massif of the Monchegorsky ore district. Zircons from anorthosites of the Javrozersky area showed some features of impact zircons: wavy extinction, blurred "aurora-like" CL image and a presence of additional bands in the Raman spectrum, which may indicate the presence of ZrSiO4 with the scheelite-type structure (reidite) surrounded by zircon material. Zircon crystals of Yavra-Varaka granophyres showed variation of Raman spectra from the core part of crystals with typical zircon Raman pattern to complete absence of spectral bands in the marginal parts and rims. There was also a transition zone between cores and marginal parts of crystals, where the Raman spectrum is "blurred". Such pattern may be associated with the transformation of crystalline zircon to diaplectic glass under the influence of shock metamorphism, since the Jarva-Varaka massif according to geological and geochemical data is compared with the Sudbury structure, for which impact origin is assumed. The work is supported by RSF grant N 16-17-10051.

  17. A 2.5 G.a. reworked sialic crust: Rb-Sr ages and isotopic geochemistry of late archaean volcanic and plutonic rocks from E. Finland

    NASA Astrophysics Data System (ADS)

    Martin, Hervé; Querré, Guirec

    1984-03-01

    In east-central Finland, Archaean terrains present three main lithologic units: a) gneissic basement, emplaced from 2.86 G.a. to 2.62 G.a., b) greenstone belt (2.65 G.a.) and c) calc-alkaline magmatism (2.50 G.a. to 2.40 G.a). Twenty three rocks of the calc-alkaline suite have been chosen for geochronologic and Rb-Sr isotopic studies. These rocks are subdivided into three groups: 1) acid volcanics from Luoma, 2) augen gneiss from Arola, and 3) post kinematik pink leucogranite from Arola. The 2.50±0.10 G.a. age of the Luoma volcanics indicates that they represent the upper part of a greenstone belt composed of a single sequence of volcanic rocks. The ages, initial 87Sr/86Sr (ISr) and major element compositions of the augen gneisses of Arola and Suomussalmi indicate that these rocks are the plutonic equivalents of the Luoma acid volcanics. The Arola pink leucogranite marks the terminal phase of Archaean magmatic activity (from 2.86 G.a. to 2.41 G.a.). This was followed by at least 0.40 G.a. of quiescence. The ISr and major element compositions suggest that the genesis of the calc-alkaline magmatic rocks involved crustal materials, but all their geochemical features cannot be explained without the participation of mafic greenstone belt materials. The first crustal components had low I and low K2O/ Na2O ratios while the younger ones (calc-alkaline magmas) had medium to high ISr and high K2O/Na2O ratios. Thus the petrogenetic processes have changed with time from ensimatic to ensialic, implying major reworking of preexisting crustal materials. This evolution leads to the accretion of the continental crust from the mantle.

  18. Granite intrusion by externally induced growth and deformation of the magma reservoir, the example of the Plasenzuela pluton, Spain

    NASA Astrophysics Data System (ADS)

    Castro, Antonio; Fernández, Carlos

    1998-09-01

    The Plasenzuela pluton in the Central Extremadura batholith in the southern Iberian Massif, is an example of permissive emplacement in relation to the tectonic development of extensional fractures in the upper continental crust. Paradoxically, this pluton has a concordant structural pattern which is classically attributed to diapirism or ballooning. This pattern consists of the following elements: (a) nearly elliptical shape in the horizontal section; (b) conformity of the pre-existing aureole structures to the shape of the pluton contacts; and (c) development of a crenulation cleavage, parallel to the contacts, in the vicinity of the pluton walls. All these features have been interpreted in many plutons as resulting from the pushing-aside of the country rock structures due to the expansion of the pluton. However, the detailed structural relationships in the aureole do not favour a forceful emplacement mechanism. By contrast, these relationships constitute prime evidence of permissive intrusion in extensional fractures. According to this interpretation, the concordant shape of the pluton was acquired by syn-plutonic opening of a mixed tensional-shear fracture, parallel to the main foliation in the host rocks, and by folding of the fracture walls together with the previous anisotropy of the country rocks. This is a growth-deformation process that can operate at local conditions in the upper continental crust giving rise to concordant syn-tectonic plutons.

  19. Record of Hybridization Preserved in Zircon, Aztec Wash Pluton, NV

    NASA Astrophysics Data System (ADS)

    Bromley, S. A.; Miller, C. F.; Claiborne, L. L.; Wooden, J. L.; Mazdab, F. K.

    2007-12-01

    The mid-Miocene Aztec Wash pluton comprises a smaller granite zone and a larger, highly heterogeneous zone in which evidence for interaction between basaltic and granitic magmas is ubiquitous. Granitic rocks in both zones show textural and compositional evidence for crystal accumulation and melt fractionation. In the heterogeneous zone, basalts have chilled, crenulate margins against granitic rocks, and there is widespread evidence for mechanical contamination of each lithology (coarse resorbed alkali feldspar in fine-grained mafic rock; mafic enclaves in granite). "Grey rocks" of intermediate composition are exposed on dm to 100's of m-scale as enclaves, pods, and initially subhorizontal sheets. They are variable texturally, but most are dominantly fine- grained and equigranular. Textures of grey rocks are consistent with rapid solidification from melt-rich magma, and, in combination with isotopic compositions intermediate between felsic and mafic rocks of the pluton, suggest an origin by near-complete homogenization of a hybrid melt (Bleick et al. 2005; Ericksen 2005). The elemental chemistry of zircon preserves information about the evolving magmatic environment in which it was hosted (Claiborne et al., 2006). Owing to its slow dissolution rate, it has the potential to survive periods of undersaturation with only partial resorption. Thus, it may record drastic shifts in T and melt chemistry that would accompany mafic-felsic hybridization. We are investigating zircon zoning patterns by cathodoluminescence (CL) and elemental compositions by SHRIMP-RG to evaluate the record of processes that they preserve. Temperatures of zircon growth are estimated using Ti-in-zircon thermometry (Watson et al. 2006), assuming a(TiO2) of ca. 0.7 (sphene +/-ilmenite are ubiquitous). Zircons from the granite zone yield estimated T's of 700-860 C, whereas those from grey rocks range from 710- 910 C. While both granite and grey zircon populations show dramatic T variations among and

  20. Use of Digital Elevation Models to understand map landforms and history of the magmatism Khibiny Massif (Kola Peninsula, Russia)

    NASA Astrophysics Data System (ADS)

    Chesalova, Elena; Asavin, Alex

    2016-04-01

    most intense free gas emission. The technical possibilities that are offered by Remote Sensing (RS) and Geographical Information Systems (GIS) facilitate the geomorphological investigation of inhospitable and inaccessible mountain areas Digital Elevation Models (DEMs) are valuable tools for approximation of the real world's continuous surface. They allow a visual analysis of the earth's surface morphology, quanti?cation of sediment volumes and the calculation of topographic derivatives such as the slope gradient, slope aspect and pro?le curvature that consume ?eld investigations and optimize time The project has been sponsored by programmm Presidium of RAS P44. Reference Ivanyuk G, Kalashnikov A, Mikhailova J, Konoplyova N, Goryainov P, Yakovenchuk V, Pakhomovsky Y. Self-Organization of the Khibiny Alkaline Massif (Kola Peninsula, Russia). In Earth Sciences, Dr. Imran Ahmad Dar(Ed.), ISBN: 978-953-307-861-8, InTech, Available from: http://www.intechopen.com/books/earth-sciences/self-organization-of-the-khibiny-alkaline -massif -kolapeninsula-russia INTECH Open Access Publisher; 2012, Head7, P.131-156.

  1. Strontium and oxygen isotopic variations in Mesozoic and Tertiary plutons of central Idaho

    USGS Publications Warehouse

    Fleck, R.J.; Criss, R.E.

    1985-01-01

    Regional variations in initial 87Sr/86Sr ratios (ri) of Mesozoic plutons in central Idaho locate the edge of Precambrian continental crust at the boundary between the late Paleozoic-Mesozoic accreted terranes and Precambrian sialic crust in western Idaho. The ri values increase abruptly but continuously from less than 0.704 in the accreted terranes to greater than 0.708 across a narrow, 5 to 15 km zone, characterized by elongate, lens-shaped, highly deformed plutons and schistose metasedimentary and metavolcanic units. The chemical and petrologic character of the plutons changes concomitantly from ocean-arc-type, diorite-tonalite-trondhjemite units to a weakly peraluminous, calcic to calcalkalic tonalite-granodiorite-granite suite (the Idaho batholith). Plutons in both suites yield Late Cretaceous ages, but Permian through Early Cretaceous bodies are confined to the accreted terranes and early Tertiary intrusions are restricted to areas underlain by Precambrian crust. The two major terranes were juxtaposed between 75 and 130 m.y. ago, probably between 80 and 95 m.y. Oxygen and strontium isotopic ratios and Rb and Sr concentrations of the plutonic rocks document a significant upper-crustal contribution to the magmas that intrude Precambrian crust. Magmas intruding the arc terranes were derived from the upper mantle/subducted oceanic lithosphere and may have been modified by anatexis of earlier island-arc volcanic and sedimentary units. Plutons near the edge of Precambrian sialic crust represent simple mixtures of the Precambrian wall-rocks with melts derived from the upper mantle or subducted oceanic lithosphere with ri of 0.7035. Rb/Sr varies linearly with ri, producing "pseudoisochrons" with apparent "ages" close to the age of the wall rocks. Measured ??18O values of the wall rocks are less than those required for the assimilated end-member by Sr-O covariation in the plutons, however, indicating that wall-rock ??18O was reduced significantly by exchange with

  2. Geochemistry of biotite granites from the Lamas de Olo Pluton, northern Portugal

    NASA Astrophysics Data System (ADS)

    Fernandes, Susana; Gomes, Maria; Teixeira, Rui; Corfu, Fernando

    2013-04-01

    In the Central Iberian Zone (CIZ) extensive crustal recycling occurred during the post-thickening extension stage of the Variscan orogeny (~330-290 Ma). After the ductile deformation phase D3 (~320-300 Ma), characterized by the intrusion of large volumes of highly peraluminous granitic magmas, rapid and drastic tectonic changes at about 300 Ma gave rise to the brittle phase of deformation D4 that controlled the emplacement of Fe-K subalkaline granites (296-290 Ma; Dias et al. 1998). The Lamas de Olo Pluton (LOP) is controlled by NE-SW and NW-SE fracture systems, probably related to the Régua-Verin fault zone (Pereira, 1989). The LOP is a medium to coarse-grained, porphyritic biotite granite, accompanied by medium- to fine grained, porphyritic biotite granite (Alto dos Cabeços- AC) and a more leucocratic, fine-grained, slightly porphyritic biotite-muscovite granite (Barragens- BA). The contacts between LO and AC are generally diffuse, whereas those to BA are sharp. In fact, the BA granite can occur in dykes and sills cutting LO and AC. Microgranular enclaves and xenoliths are very rare. The LOP intrudes the Douro Group, presumably of Precambrian to Cambrian age, and two-mica granites from the Vila Real composite massif. The LOP granites consist of quartz, microcline, plagioclase, biotite, zircon, titanite, tourmaline apatite, fluorite, ilmenite, magnetite, and rutile, with muscovite in BA granite and rare allanite in the LO and AC granites. The plagioclase composition is of oligoclase (An12) - andesine (An35) for LO granite, albite (An9) - andesine (An30) for CA granite and albite (An5) - oligoclase (An20) for BA granite. There are decreases in: a) anorthite content from phenocryst to matrix plagioclase; b) Ba content from phenocryst to matrix microcline in all granites. The Fe2+ biotite has a composition similar to that of biotite from calc-alkaline to sub-alkaline rock series. The LO and AC granites are meta- to peraluminous with ASI variable between 1.05 and 1

  3. Modulators of intestinal alkaline phosphatase.

    PubMed

    Bobkova, Ekaterina V; Kiffer-Moreira, Tina; Sergienko, Eduard A

    2013-01-01

    Small molecule modulators of phosphatases can lead to clinically useful drugs and serve as invaluable tools to study functional roles of various phosphatases in vivo. Here, we describe lead discovery strategies for identification of inhibitors and activators of intestinal alkaline phosphatases. To identify isozyme-selective inhibitors and activators of the human and mouse intestinal alkaline phosphatases, ultrahigh throughput chemiluminescent assays, utilizing CDP-Star as a substrate, were developed for murine intestinal alkaline phosphatase (mIAP), human intestinal alkaline phosphatase (hIAP), human placental alkaline phosphatase (PLAP), and human tissue-nonspecific alkaline phosphatase (TNAP) isozymes. Using these 1,536-well assays, concurrent HTS screens of the MLSMR library of 323,000 compounds were conducted for human and mouse IAP isozymes monitoring both inhibition and activation. This parallel screening approach led to identification of a novel inhibitory scaffold selective for murine intestinal alkaline phosphatase. SAR efforts based on parallel testing of analogs against different AP isozymes generated a potent inhibitor of the murine IAP with IC50 of 540 nM, at least 65-fold selectivity against human TNAP, and >185 selectivity against human PLAP. PMID:23860652

  4. Alkaline battery, separator therefore

    NASA Technical Reports Server (NTRS)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  5. Paleomagnetic results from the Shasta Bally Plutonic Belt in the Klamath Mountains Province, northern California

    NASA Astrophysics Data System (ADS)

    Mankinen, Edward A.; Irwin, William P.; Grommé, C. Sherman

    1988-01-01

    Available paleomagnetic data show approximately 100° of clockwise rotation for Permian and Triassic strata of the Eastern Klamath terrane. Jurassic strata of this terrane are rotated approximately 60° clockwise, which is comparable to rotations reported for Jurassic plutons that occur elsewhere in the Klamath Mountains province. Paleomagnetic data obtained during the present study from the Shasta Bally belt of Cretaceous plutons indicate 25.7° ± 13.6° of clockwise rotation for the province since Early Cretaceous time (≃ 136 Ma). The waning stages of rotation at the time of emplacement of the Shasta Bally belt plutons, which was closely followed by deposition of basal strata (Lower Cretaceous) of the Great Valley sequence, probably represents completion of accretion of the province to cratonic North America.

  6. Reconnaissance geochemical exploration of plutons of syenite and shonkinite, southern Asir, Kingdom of Saudi Arabia

    SciTech Connect

    Overstreet, W.C.; Assegaff, A.B.; Hussain, M.A.; Naqvi, M.I.; Selner, G.I.; Matzko, J.J.

    1985-01-01

    Reconnaissance geochemical exploration for rare metals in plutons of syenite and shonkinite disclosed generally less than 20 ppM Nb in rocks, wadi sediments, and concentrates. The sparsity of Nb is accompanied by low values for La, Sn, W, Y, and Zr and relatively high but insignificant values for Be and Mo. Base and precious metals are either below their respective limits of determination in the various sample media or are present at background levels commensurate with average crustal abundances in felsic rocks. Pegmatite dikes associated with the syenite plutons are rare and lack vermiculite. The present investigation disclosed no possible ore deposits in the plutons covered by the field work. Known kyanite-topaz-natroalunite rocks in the vicinity of the surveyed areas should be examined for possible deposits of Cu, Mo, or Au associated with high-alumina hydrothermal deposits. 27 refs., 7 figs., 21 tabs.

  7. Physical Properties and Distribution of Intrusive Rocks (Plutons) in the Great Basin

    NASA Astrophysics Data System (ADS)

    Ponce, D. A.; Watt, J. T.; Glen, J. M.

    2010-12-01

    The distribution of intrusive rocks throughout the Great Basin is important because many plutons are associated with base and precious metal mineral deposits, and may provide insights on regional magmatism and tectonism. Combined information on their physical properties and geophysical signatures will allow improvements on their inferred horizontal extent and facilitate modeling their subsurface structure. Physical property measurements of over 1700 plutonic rock samples in the Great Basin, excluding those in the Sierra Nevada, show an average grain density of about 2670 and a range of about 2260 to 3200 kg/m3; show an average saturated bulk density of about 2630 and a range of about 2290 to 3050 kg/m3; an average magnetic susceptibility of about 0.007 and range from essentially non-magnetic to 0.126 SI-units (equivalent to just over 3 per cent magnetite). As a comparison, over 6,000 granitic samples in the Sierra Nevada (Sikora et al., 1991) have an average grain density of about 2690 and a range of about 2420 to 2780 kg/m3; an average magnetic susceptibility of about 0.006 and range from essentially non-magnetic to 0.016 SI-units (equivalent to about 0.4 per cent magnetite). Remanent magnetizations were measured for selected plutons, for example the remanent magnetization of the Ibapah pluton in the Deep Creek Range, Utah is relatively low and has a Koenigsberger ratio (the ratio between remanent and induced magnetization) of about 0.1. In Nevada, previous pluton extents (Grauch et al., 1988; Grauch , 1996) have been only slightly modified. For example, the Cretaceous to Jurassic stock at Blue Mountain, north-central Nevada (Wilden, 1964) is now mapped as a diorite dike swarm (Wyld, 2002) and thought to be mid-Miocene and related to the inception of the Yellowstone Hotspot (Ponce et al, 2010). Magnetic and gravity data indicate that a possible pluton (or other magnetic basement rock), the top of which could be at moderate crustal depths, is skewed from the

  8. A Comparative Size-Composition-Distribution Analysis Of Xenoliths In Plutons

    NASA Astrophysics Data System (ADS)

    Gates, K.; Marko, W. T.; Yoshinobu, A. S.

    2012-12-01

    Field geologists and petrologists have long recognized the significance of xenoliths both in terms of their presence, as well as their conspicuous absence within plutonic rocks. However, few quantitative studies exist on the size and distribution of xenoliths in plutons. We report an exploratory set of size, composition, and distribution studies of xenoliths from a variety of different plutons of granodiorite to diorite composition that bear on processes of xenolith a) incorporation into magmas, b) deformation and displacement in magma chambers, c) preservation in magmas, and d) dissolution and melting in magmas. Four plutons, assembled at depths ranging from subvolcanic to 25 km, have been studied in detail (Jackass Lakes granodiorite, CA; Andalshatten granodiorite and Vega granodiorite, Norway; and Wooley Creek qtz-diorite, CA); two additional plutons (Krakfjellet, Norway, Main Donegal, Ireland) have been evaluated based on published observations. The following observations are summarized: 1) xenoliths in the studied intrusions range in size from sub-mm2 to > km2 and from << 1 to > 8% of total intrusion area, exclusive of screens that may be attached to the host rocks in 3D; 2) in plutons that intrude metasedimentary host rocks, xenoliths of carbonate/quartzite/bte-schist are common whereas pelite and pelitic migmatite are uncommon; 3) statistical size-frequency analysis of a variety of xenolith lithologies display fractal dimensions with D ~ 1 to 3 in log space over a range of sizes. However, in most cases, the density of small xenolith sizes diminishes; 4) plutons with compositions corresponding to higher solidi (e.g., tonalites, qtz diorites, gabbros, etc.) tend to contain migmatitic xenoliths (where bulk composition is appropriate), some of which underwent partial melting in situ; 5) virtually all xenoliths from mm to km in scale have been displaced relative to a fixed host-rock reference frame; none can be shown to be in situ; 6) in all plutons examined

  9. Use of olivine and plagioclase saturation surfaces for the petrogenetic modeling of recrystallized basic plutonic systems

    NASA Technical Reports Server (NTRS)

    Hanson, G. N.

    1983-01-01

    During petrogenetic studies of basic plutonic rocks, there are at least three major questions to be considered: (1) what were the relative proportions of cumulate crystals and intercumulus melt in a given sample? (2) what is the composition and variation in composition of the melts within the pluton? and (3) what is the original composition of the liquids, their source and evolution prior to the time of emplacement? Use of both saturation surfaces can place strong limits on the compositions of potential cumulate phases and intercumulus melts. Consideration of appropriate trace elements can indicate whether a sample is an orthocumulate, adcumulate or mesocumulate. Thus, when trace element and petrographic data are considered together with the saturation surfaces, it should be possible to begin to answer the three major questions given above, even for strongly recrystallized basic plutons.

  10. Berdyaush pluton of rapakivi granites, South Urals: New data on the geological structure and geodynamic evolution

    NASA Astrophysics Data System (ADS)

    Snachev, V. I.; Bazhin, E. A.

    2016-01-01

    The new version of the geological structure of the Berdyaush pluton (a single intrusion of rapakivi granites in the Urals) presented in this paper is significantly distinct from the previous structural schemes. Rapakivi granites compose no more than 10-20% of the area of the pluton and they are widespread only in its northeastern and southwestern flanks. The contacts between gabbro (I phase), hybrid syenodiorites (II phase), and rapakivi granites (III phase) are transitional, metasomatic. The hybrid syenodiorites and rapakivi granites are formed after gabbroic rocks as a result of their intense thermal and metasomatic transformation by the deep fluids. The driving force of this process could be the unilateral compression of the Berdyaush pluton resulting from formation of the eastward continental rift in the beginning of the Middle Riphean.

  11. Experience in applying acoustopolarization method for rock samples from the Kola (SG-3), German (KTB) and Finnish (OKU) investigation boreholes

    NASA Astrophysics Data System (ADS)

    Gorbatsevich, Felix F.

    2013-04-01

    The Kola Superdeep Borehole (SG-3) was drilled in the NW-part of the Kola Peninsula [1]. The borehole intersected the lower Proterozoic complex (0-6848 m) of the Pechenga Formation and an Archaean granite and metamorphic complex (6848-12261 m). Our investigations show that rocks of the Archaean complex (paragneiss, metabasite, amphibolites) have high elastic anisotropy. It correlates with breakouts from the walls of the borehole and its inclination (deviation) from the vertical during drilling. Because of this when drilling SG-3 at a depth of 7.7 km to 10.1 km accidents occurred with the loss of the drill string part. Sinking the German drill hole ?-? (9101 m) was also accompanied by complications during its drilling [2]. The drill hole was drilled in the crystalline basement of the Bohemian massif in the south of Germany. The main rocks composing the massif are paragneiss, metabasite, granite and metasedimentary rocks. Our investigations of the ?-? samples from the 4.1-7.1 km interval also showed a high level of elastic anisotropy. The investigation drill hole Outokumpu (OKU) located in SE Finland, reached a final depth of 2516 m. The drill hole has passed through mica schists, biotite gneiss, serpentinite and pegmatite granite. Excluding pegmatite granite, all rocks have a high level of elastic anisotropy. Joint analyses of rock samples from SG-3, ?-? and OKU showed that the use of the acoustopolariscopy method can reveal intervals with breakouts and inclinations of the drill hole from the vertical. Elastic anisotropy monitoring of rocks performed by the acoustopolariscopy method will prevent accidents during sinking wells. 1. Gorbatsevich, F.F. & Smirnov, Yu.P. 2000. Kola Superdeep Borehole: 3-D model of elastic anisotropy of crystalline rocks in the upper and middle crust. In: The results of the study of the deep substance and physical processes in the Kola Superdeep Borehole section down to a depth of 12261 m. (Eds. F.P. Mitrofanov, F.F. Gorbatsevich). Apatity

  12. Evaluation of Alkaline Cleaner Materials

    NASA Technical Reports Server (NTRS)

    Partz, Earl

    1998-01-01

    Alkaline cleaners used to process aluminum substrates have contained chromium as the corrosion inhibitor. Chromium is a hazardous substance whose use and control are described by environmental laws. Replacement materials that have the characteristics of chromated alkaline cleaners need to be found that address both the cleaning requirements and environmental impacts. This report will review environmentally friendly candidates evaluated as non-chromium alkaline cleaner replacements and methods used to compare those candidates one versus another. The report will also list characteristics used to select candidates based on their declared contents. It will also describe and evaluate methods used to discriminate among the large number of prospective candidates.

  13. Perspectives of humic substances application in remediation of highly heavy metals contaminated soils in Kola Subarctic

    NASA Astrophysics Data System (ADS)

    Tregubova, Polina; Turbaevskaya, Valeria; Zakharenko, Andrey; Kadulin, Maksim; Smirnova, Irina; Stepanov, Andrey; Koptsik, Galina

    2016-04-01

    Northwestern part of Russia, the Kola Peninsula, is one of the most heavy metals (HM) contaminated areas in the northern hemisphere. The main polluters, mining-and-metallurgical integrated works "Pechenganikel" and "Severonikel", are surrounded by heavily damaged barren lands that require remediation. The main contaminating metals are Ni and Cu. Using of exogenous humic substances could be possible effective and cost-efficient solution of HM contamination problem. Rational application of humates (Na-K salts of humic acids) can result in improvement of soil properties, localization of contamination and decreasing bioavailability through binding HM in relatively immobile organic complexes. Our research aim was to evaluate the influence of increasing doses of different origin humates on i) basic properties of contaminated soils; ii) mobility and bioavailability of HMs; iii) vegetation state and chemistry. In summer 2013 a model field experiment was provided in natural conditions of the Kola Peninsula. We investigated the Al-Fe-humus abrazem, soil type that dominates in technogenic barren lands around the "Severonikel" work. These soils are strongly acid: pHH2O was 3.7-4.1; pHKCl was 3.4-4.0. The exchangeable acidity is low (0.8-1.6 cmol(+)/kg) due to the depletion of fine particles and organic matter, being the carriers of exchange positions. The abrazems of barrens had lost organic horizon. 12 sites were created in 1 km from the work. In those sites, except 2 controls, various amendments were added: i) two different by it's origin types of humates: peat-humates and coal-humates, the last were in concentrations 0.5% and 1%; ii) lime; iii) NPK-fertilizer; iv) biomates (organic degradable cover for saving warm and erosion protection). As a test-culture a grass mixture with predominance of Festuca rubra and Festuca ovina was sowed. As a result we concluded that humates of different origin have unequal influence on soil properties and cause decreasing as well as

  14. A Tale of Two Plutons: Using Monazite to Reconstruct the Fluid History of Contact Metamorphic Aureoles

    NASA Astrophysics Data System (ADS)

    Ayers, J. C.; Crombie, S.; Miller, C.; Luo, Y.; Loflin, M.

    2006-12-01

    The rare earth phosphate monazite can be a powerful tool for characterizing the timing and spatial extent of fluid infiltration during contact metamorphism. We used an ion microprobe to investigate how wallrock monazite responded to the intrusion of two different granitic plutons, the Cretaceous Birch Creek Pluton (BCP) in the White Mountains of eastern California and the Miocene Searchlight pluton in southern Nevada. The contact metamorphic aureoles of both plutons contain monazite and display evidence of alteration by acidic magmatic fluids (sericitization). Contact metamorphism occurred at conditions under which monazite in granitic systems has been shown to be susceptible to hydrothermal alteration: mildly acidic fluids at temperatures of ~250-400C and pressures of ~0.15-0.4 GPa. Monazite from the hydrothermal aureole of the BCP records the infiltration of magmatic fluids into the Early Cambrian Deep Spring Formation (DSF) containing metaquartzites and metasandstones. Monazites in the DSF < 0.6 km from the contact show patchy zoning and have Th-Pb ages and oxygen isotope compositions similar to monazites in the Birch Creek granite but different from monazites > 0.6 km from the contact, suggesting that they dissolved and reprecipitated in infiltrating magmatic fluids. In contrast, the stable isotope compositions of monazites and host rocks (Proterozoic gneisses and the Cretaceous Ireteba granite) on the flanks of the Searchlight pluton do not show evidence of hydrothermal alteration, even though many of the monazites display patchy zoning and ages corresponding to the Searchlight intrusion. The Searchlight gold-silver-copper mining district is primarily located in the roof of the Searchlight intrusion, which contains rocks that were intensely hydrothermally altered but contain no monazite. Searchlight magmatic fluids were strongly focused into the roof zone, with little or no fluid escaping out the sides of the Searchlight pluton during crystallization. Monazite

  15. Contact metamorphism associated with emplacement of the Papoose Flat pluton, Inyo Mountains, California

    SciTech Connect

    Nyman, M.W.; Law, R.D.; Morgan, S.S. )

    1992-01-01

    Petrologic investigation of marbles and calc-silicates found within L-S tectonites from the western part of the Papoose Flat pluton's aureole has been undertaken to determine the wallrock thermal gradients associated with pluton emplacement. Temperatures of metamorphism of marbles were determined using Cal-Dol geothermometry coupled with constrains from phase equilibria of both carbonates and interbedded pelites. Throughout the aureole maximum temperatures for samples closest to the contact range from 475--500 C. The phase assemblage in these samples is Cal-Dol-Qtz-Ms-Phl [+-] Hb [+-] Chl. Temperatures decrease rapidly to ambient country rock conditions within 30--90 m away from the contact. Thermal gradients around the strongly deformed western margin of the pluton appear to all be linear and fall into three distinct groups: Type 1. gradients of 0--2.5 C/10m, Type 2. gradients of 13--18 C/10m and, Type 3. gradients of 47--59 C/10m. The strongly deformed nature of the contact rocks supports post- or synmetamorphic thinning of the aureole whereas the presence of skarn mineralization and strongly altered pelitic aureole rocks suggest a convective control to the thermal gradients. Portions of the aureole which have Type 1 gradients may represent areas where (1) convection was more efficient and therefore maintained a relatively steady state thermal profile, (2) introduction of new magma batches during pluton emplacement kept aureole temperatures constant or (3) the pluton-wallrock contact is oriented such that each sample locality is equidistant from the pluton margin. Thermal modeling using both convective and conductive parameters is currently being undertaken to further evaluate these models.

  16. Late Cretaceous ductile deformation, metamorphism and plutonism in the Piute Mountains, eastern Mojave Desert

    SciTech Connect

    Fletcher, J.M.; Karlstrom, K.E. )

    1990-01-10

    Late Cretaceous deformation in the Piute Mountains involved ductile thrusting on a network of anastomosing northeast and southwest directed shear zones. The shear zones often separate Proterozoic lithologies with strong competency contrasts, suggesting that Proterozoic crustal anisotropies were important in controlling the geometry of the shear zone network. Shear zones now divide the crust into wedge- and lozenge-shaped blocks. The Piute Mountains can be separated into two kinematic domains, each characterized by a dominant sense of shear. Thrusting in the southwest directed kinematic domain ended at 85 {plus minus} 7 Ma, the age of the late synkinematic East Piute pluton. Thrusting in the northeast directed kinematic domain could have lasted until 74 {plus minus} 3 Ma, the age of the Lazy Daisy pluton. Postthrusting northwest-southeast shortening produced a second generation of upright open folds with a northeast striking subvertical crenulation cleavage. F{sub 2} strain increases toward the south and is concentrated around the margins of the Lazy Daisy pluton. This deformation was synchronous with pluton emplacement. Lake Cretaceous peak metamorphism outlasted all ductile deformation. Peak metamorphic grade increases from upper greenschist facies in the north to upper amphibolite facies as the Lazy Daisy pluton is approached. Temperature and pressure of approximately 450 C and 2.5-4.0 kbar were achieved during ductile thrusting. Temperatures of 500-540 C existed at the onset of upright open folding, and peak temperatures as high as 620 C near the Lazy Daisy pluton occurred after F{sub 2} upright folding. All penetrative deformation ended before 72-71 Ma, by which time the area had cooled to below 300 C.

  17. Structure and emplacement of granite plutons in the Paleoproterozoic crust of Eastern Burkina Faso: rheological implications

    NASA Astrophysics Data System (ADS)

    Vegas, Nestor; Naba, Seta; Bouchez, Jean Luc; Jessell, Mark

    2008-11-01

    The Fada N'Gourma area in Burkina Faso is underlain by Paleoproterozoic rocks that make the northeastern West-African Craton. This region is composed of NE-trending volcano-sedimentary belts and foliated tonalites, affected by several shear zones. A generation of younger, ˜2100 Ma-old, non-foliated biotite-bearing granites intrudes the former rock units. We have investigated the younger granite pluton of Kouare that was previously considered as forming a single body with the pluton of Satenga to the west, a pluton which likely belongs to the ˜20 Ma more recent Tenkodogo-Yamba batholith. Magnetic fabric measurements have been combined with microstructural observations and the analysis of field and aeromagnetic data. The granite encloses angular enclaves of the host tonalites. Magmatic microstructures are preserved inside the pluton and solid-state, high-temperature deformation features are ubiquitous at its periphery. The presence of steeply plunging lineations in the pluton of Kouare and its adjacent host-rocks suggests that large volumes of granitic magmas became crystallized while they were ascending through the crust that was softened and steepened close to the contact. Around Kouare, the foliation in the host tonalites conforms with a map-scale, Z-shaped fold in between NNE-trending shear zones, implying a bulk clockwise rotation of the material contained in-between the shear zones, including the emplacing pluton. Regionally, the Fada N'Gourma area is concluded to result from NW-shortening associated with transcurrent shearing and vertical transfer of granitic magmas. This study concludes that the ˜2200 Myears old juvenile crust of Burkina Faso was brittle before the intrusion of the biotite-granites, became softened close to them and that gravity-driven and regional scale wrench tectonics were active together.

  18. Spatiotemporal relationships of dike magmatism in the Kola region, the Fennoscandian Shield

    NASA Astrophysics Data System (ADS)

    Fedotov, Zh. A.; Bayanova, T. B.; Serov, P. A.

    2012-11-01

    A brief geological and petrographic characterization of the Early Precambrian dike complexes of the Kola region is given along with data on new estimates of dike age and analysis of their distribution over the entire Fennoscandian Shield. The emplacement of dikes in the Archean core of the shield continued after consolidation of the sialic crust 2.74-1.76 Ga ago. After the Svecofennian Orogeny, dikes continued to form in the west in the area of newly formed crust, while the amagmatic period began in the Archean domain. The intense formation of dikes in the Svecofennian domain lasted approximately for 1 Ga (1.8-0.84 Ga). The younger igneous rocks in the crustal domains of different age are less abundant and localized at their margins. A similar distribution of dikes is characteristic of other shields in different continents. This implies that the formation of the sialic crust in the shields is not completed by its consolidation and formation of the craton. For 1 Ga after completion of this process, the crust is underplated by mantle-derived magmas. This process is reflected at the Earth's surface in the development of mantle-derived mafic and anorogenic granitoid magmatism. The process of crust formation is ended as the subcratonic lithosphere cools and the amagmatic period of the craton history is started. Beginning from this moment, the manifestations of cratonic magmatism were related either to the superposed tectonomagmatic reactivation of the cold craton under the effect of crust formation in the adjacent mobile belts or to the ascent of mantle plumes.

  19. In vivo evaluation of interaction between aqueous seed extract of Garcinia kola Heckel and ciprofloxacin hydrochloride.

    PubMed

    Esimone, Charles O; Nwafor, Sunday V; Okoli, Charles O; Chah, Kennedy F; Uzuegbu, David B; Chibundu, Chinedu; Eche, Mike A; Adikwu, Micheal U

    2002-01-01

    The effect of Garcinia kola seed extract (100 mg/kg) on the pharmacokinetic and antibacterial effects of ciprofloxacin hydrochloride (40 mg/kg) was studied. The results (mean +/- SEM) indicated that concurrent administration of both agents significantly (P < 0.05) decreased average serum concentration, peak serum concentration, and elimination rate of ciprofloxacin HCl, whereas the half-life and clearance rate were increased. The decrease in clearance rate was not significant. There was no difference in time to peak plasma concentration of ciprofloxacin HCl in both groups (n = 5), which occurred at 1 hour. However, the peak plasma concentration of ciprofloxacin HCl was 46.90 +/- 9.50 microg/mL in the group that received ciprofloxacin HCl alone as against 35.80 +/- 9.30 microg/mL noted in the group that received both agents (difference of 22.24%). At 2.5 hours and longer, the values were higher in the group that received both agents, but these were not statistically significant. The reciprocal serum inhibitory titer (SIT) was 33.33 and 50.00% higher in group that received ciprofloxacin HCl alone at 1 and 2.5 hours, respectively; the highest value for both groups being at 1 hour. In contrast, at 4 hours, the value of reciprocal SIT was 66.67% higher in the group that received both agents and at 24 hours, the value was zero for both groups. The observed pharmacokinetic and antibacterial interactions at various time interval indicate biphasic interaction. The interaction was antagonistic at 1 and 2.5 hours, but exhibited potentiation at 4 hours. The precise mechanism underlying the observed biphasic interaction is not fully understood. PMID:12115015

  20. Petrology, geochemistry and thermobarometry of the northern area of the Flamenco pluton, Coastal Range batholith, northern Chile. A thermal approach to the emplacement processes in the Jurassic andean batholiths

    NASA Astrophysics Data System (ADS)

    Rodríguez, Natalia; Díaz-Alvarado, Juan; Rodríguez, Carmen; Riveros, Karl; Fuentes, Paulina

    2016-04-01

    The Flamenco pluton is part of a N-S alignment of Late Triassic to Early Jurassic intrusive belt comprising the westernmost part of the Coastal Range batholith in northern Chile. The Jurassic-Cretaceous voluminous magmatism related to subduction in the western active continental margin of Gondwana is emplaced in the predominantly metasedimentary Paleozoic host-rocks of the Las Tórtolas formation, which in the northern area of the Flamenco pluton present an intense deformation, including the Chañaral mélange. Geochemically, the Flamenco pluton shows a wide compositional variability (SiO2 between 48wt % and 67wt %). Gabbros, Qtz-diorites and tonalites, mesocratic and leucocratic granodiorites are classified as calc-alkaline, calcic, magnesian and metaluminous magmatism. Flamenco granitoids define cotectic linear evolution trends, typical of magmatic fractionation processes. Geochemical trends are consistent with magmas evolved from undersaturated and low-pressure melts, even though the absence of transitional contacts between intrusive units precludes in-situ fractionation. Although some granodioritic samples show crossed geochemical trends that point to the compositional field of metasediments, and large euhedral prismatic pinnite-biotite crystals, typical Crd pseudomorph, are observed in contact magmatic facies, geochemical assimilation processes are short range, and the occurrence of host-rocks xenoliths is limited to a few meters from the pluton contact. A thermal approach to the emplacement process has been constrained through the thermobarometric results and a 2D thermo-numerical model of the contact aureole. Some Qtz-diorites and granodiorites located in the north area of the pluton exhibit granulitic textures as Hbl-Pl-Qtz triple junctions, poikiloblastic Kfs and Qtz recrystallization. The Hbl-Pl pairs have been used for the thermobarometric study of this metamorphic process, resulting granoblastic equilibrium temperatures between 770 and 790 °C, whereas

  1. Comparing magnetic and magmatic fabrics to constrain the magma flow record in La Gloria pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Payacán, Italo; Gutiérrez, Francisco; Gelman, Sarah E.; Bachmann, Olivier; Parada, Miguel Ángel

    2014-12-01

    This contribution illustrates a case study of a pluton (La Gloria pluton; LGP) where magnetic and magmatic fabrics are locally decoupled. We compare the magmatic fabric with the available magnetic fabric data to explore their abilities and elucidate the magma flow record of LGP. Results indicate that magnetic (controlled by multi-domain magnetite) and magmatic fabrics are generally consistent throughout LGP. Foliations define an axisymmetric pattern that gradually changes from vertical near lateral margins to less steep in the pluton interior, whereas lineations are subhorizontal following the elongation direction of the pluton. However, samples at the pluton center show marked differences between both fabrics: magnetic fabrics indicate subhorizontal magnetic lineations and foliations, and magmatic fabrics indicate subvertical lineations and foliations. Both magnetic and magmatic fabrics are interpreted to record strain caused by magma flow during thermal convection and lateral magma propagation at the transition between low and high crystallinity stages. We suggest that fabrics acquisition and consistency were determined by shear conditions (pure/simple shear rates ratio) and the orientation of the magma flow direction with respect to a rigid boundary (critical crystalline region) of the pluton. Magmatic fabric differs at the center of the pluton because pure shear is dominant and ascendant flows are orthogonal to the horizontal rigid boundary. LGP represents a whole-scale partly molten magma reservoir, where both thermal convection and lateral propagation of the magma are recorded simultaneously. This study highlights the importance of characterizing both fabrics to properly interpret magma flow recorded in plutons.

  2. Modelling and Evaluation of Environmental Impact due to Continuous Emissions of the Severonickel Plant (Kola Peninsula)

    NASA Astrophysics Data System (ADS)

    Mahura, A.; Gonzalez-Aparicio, I.; Nuterman, R.; Baklanov, A.

    2012-04-01

    In this study, evaluation of potential impact - through concentration, deposition and loadings patterns - on population and environment due to continuous anthropogenic emissions (on example of sulfates) of the Cu-Ni smelters of the Russian North is given. To estimate impact, the Danish Emergency Response Model for Atmosphere (DERMA) was employed to perform long-term simulations of air concentration, time integrated air concentration (TIAC), dry (DD) and wet (WD) deposition patterns resulting from continuous emissions of the Severonickel smelters located on the Kola Peninsula (Murmansk region, Russia). To perform such simulations the 3D meteorological fields (from the European Center for Medium-Range Weather Forecasts, ECMWF) for the year 2000 were used as input. For simplicity, it has been assumed that normalized releases of sulfates from smelters location occurred at a constant rate every day. For each daily release the atmospheric transport, dispersion, dry and wet deposition due to removal processes were estimated during 10 day interval. Output from these long-term simulations is an essential input for evaluation of impact, doses, risks, and short- and long-term consequences, etc. Detailed analyses of simulated concentration and deposition fields allowed evaluating the spatial and temporal variability of resulted patterns on different scales. Temporal variability of both wet and dry deposition as well as their contribution into total deposition have been estimated. On an annual scale, the concentration and deposition patterns were estimated for the most populated cities of the North-West Russia. The modeled annual fields were also integrated into GIS environment as well as layers with population density (from the Center for International Earth Science Information Network, CIESIN) and standard administrative division of the North-West Russia and bordering countries. Furthermore, the estimation of deposited amounts (loadings) of sulfates for selected regions of

  3. Late Cretaceous and early Tertiary plutonism and deformation in the Skagit Gneiss Complex, north Cascade Range, Washington and British Columbia

    USGS Publications Warehouse

    Haugerud, R.A.; Van Der Heyden, P.; Tabor, R.W.; Stacey, J.S.; Zartman, R.E.

    1991-01-01

    The Skagit Gneiss Complex forms a more-or-less continuous terrane within the North Cascade Range. The complex comprises abundant plutons intruded at mid-crustal depths into a variety of metamorphosed supracrustal rocks of both oceanic and volcanic-arc origin. U-Pb zircon ages from gneissis plutons within and near the Skagit Gneiss Complex indicate magmatic crystallziations between 75 and 60 Ma. Deformation, recrystallization, and migmatization in part postdate intrusion of the 75-60 Ma plutons. This latest Cretaceous and earliest Tertiary plutonism and migmatization may reflect thermal relaxation following early Late Cretaceous orogeny. The complex was ductilely extended northwest-southeast shortly after intrusion of granite dikes at ~45 Ma, but before emplacement of the earliest (~34 Ma) plutons of the Cascade arc. -from Authors

  4. Map showing the distribution and characteristics of plutonic rocks in the Tonopah 1 degree by 2 degrees Quadrangle, central Nevada

    USGS Publications Warehouse

    John, D.A.

    1987-01-01

    The accompanying table includes the name (if any) of the pluton and its location, the age of the pluton (either a radiometric age or an age inferred from field relations), modal composition, texture, mineralogy, hydrothermal alteration and mineralization related to the pluton, the source of mapping shown on this map, and published references on the pluton. Radiometric ages are either published K-Ar and fission track ages or new whole-rock Rb-Sr ages determined by A. C. Robinson on samples collected either for this study or as part of regional Sr-isotope studies by R.W. Kistler and A.C. Robinson. K-Ar ages published prior to 1977 are corrected using the new I.U.C.S. constants (Steiger and Jager, 1977). Muscovite alteration ages are reported for several plutons and represent minimum ages for emplacement of these plutons. Compositional classification follows the T. J. G.S. system (“Streckeisen, 1976) and is based either on modal analyses of slabs or estimates from hand specimens. All modes, unless otherwise noted, were measured in this study. The number of modes determined is shown in parentheses, and the range in volume percent of major minerals is given. Where no modal data are available, the color index (percentage of mafic minerals) and major mafic minerals are given for most plutons. Data tabulated on hydrothermal alteration and mineralization related to plutons are based on observations made during field studies for this project. Clear genetic relation between granitic plutonism and several mineral deposits previously attributed to granitic plutonism were not substantiated, and these inconsistencies are noted in the table.

  5. Isotopic disequilibrium among commingled hybrid magmas: Evidence for a two-stage magma mixing-commingling process in the Mt. Perkins Pluton, Arizona

    SciTech Connect

    Metcalf, R.V.; Smith, E.I.; Reed, R.C.

    1995-09-01

    The syn-extensional Miocene Mt. Perkins pluton, northwestern Arizona, cooled rapidly due to its small size (6 km{sup 2}) and shallow emplacement (7.5 km) and allows examination of commingled rocks that experienced little isotopic exchange. Within the pluton, quartz dioritic to granodioritic host rocks (58-68 wt% SiO{sub 2}) enclose dioritic enclaves (50-55 wt% SiO{sub 2}) and a portion contains enclave-free granodiorite (70-74 wt% SiO{sub 2}). Fine-grained, crenulate enclave margins and a lack of advanced mixing structures (e.g., schlieren, flow fabrics, etc.) indicate an incipient stage of commingling. Isotopic variation between enclaves and enclosing host rocks is large (6.8 to 10.6 {epsilon}{sub Nd} units; 0.0036 to 0.0046 {sup 87}Sr/{sup 86}Sr units), suggesting isotopic disequilibrium. Comparison of an enclave core and rim suggests that isotopic exchange with the host magma was limited to the enclave rim. Enclaves and hosts collectively form a calc-alkaline suite exhibiting a large range of {epsilon}{sub Nd} (+1.2 to -12.5) and initial {sup 87}Sr/{sup 86}Sr (0.705 to 0.71267) with a correlation among {epsilon}{sub Nd}, initial {sup 87}Sr/{sup 86}Sr, and major and trace element compositions. Modeling suggests that the suite formed by magma hybridization involving magma mixing accompanied by fractional crystallization. The magma mixing must have predated commingling at the present exposure level and indicates a larger mixing chamber at depth. Isotopic and trace element data suggests mixing end-members were asthenospheric mantle-derived mafic and crustal-derived felsic magmas. Fractional crystallization facilitated mixing by reducing the rheological contrasts between the mafic and felsic mixing end-members. 58 refs., 11 figs., 3 tabs.

  6. Three hydroxylated lupeol-based triterpenoid esters isolated from the Eastern Nigeria mistletoe parasitic on Kola acuminata.

    PubMed

    Omeje, Edwin Ogechukwu; Osadebe, Patience Ogoamaka; Esimone, Charles Okechukwu; Nworu, Chukwuemeka Sylvester; Kawamura, Akira; Proksch, Peter

    2012-01-01

    Column fractionation and purification of an n-hexane fraction led to the isolation of three lupeol-based triterpenoid esters from the leaves of the Eastern Nigeria mistletoe, Loranthus micranthus Linn parasitic on a local kola nut tree, Kola acuminata. These three compounds were adequately characterised using a combination of UV/visible, IR, NMR (¹³C-NMR and ¹H-NMR), DEPT, MS and two-dimensional correlation (H-H COSY, Hetero-nuclear Single Quantum Correlation (HSQC), HMBC, NOE and NOESY) studies as 7β,15α-dihydroxyl-lup-20(29)-ene-3β-esters of palmitic (I), stearic (II) and eicosanoic acids (III). The characterisation of other isolated compounds is ongoing. Remarkably, this is the first report of the existence of fatty acid esters of an unusual 7β,15α-dihydroxylated lupeol in the Eastern Nigeria mistletoe. These isolated compounds might contribute in part to the numerous established bio-activities of the Eastern Nigeria mistletoes. PMID:22007932

  7. Environmental impact assessment of the mining and concentration activities in the Kola Peninsula, Russia by multidate remote sensing.

    PubMed

    Rigina, Olga

    2002-04-01

    On the Kola Peninsula, the mining and concentration industry exerts anthropogenic impact on the environment. Tailing dumps cause airborne pollution through dusting, and waterborne pollution due to direct dumping and accidental releases. The objectives were: (1) to analyse multidate satellite images for 1964-1996 to assess the environmental pollution from the mining and concentration activity in the Kola in temporal perspective; (2) to evaluate remote sensing methods for integrated environmental impact assessment. The area of mining and industrial sites steadily expands and amounted to 94 km2 in 1996. The polluted water surface amounted to at least 150 km2 through dumping in 1978 and to 106 km2 in 1986 due to dusting. Thus, the impact from the mining and concentration activity should be reconsidered as more significant than it was officially anticipated. In the past the main mechanism of pollution was direct dumping into the lakes. Currently and in future, airborne pollution after dusting storms will dominate. The effective recultivation of the tailing dumps will be a long-term process. For effective assessment of impacts from the mining and concentration industry, remote sensing methods should be complemented by in-situ measurements, fieldwork, and mathematical modelling. PMID:15900663

  8. Preliminary Results of Marine Electromagnetic Sounding with a Powerful, Remote Source in Kola Bay off the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kruglyakov, M.; Zhdanov, M. S.; Grigor'ev, V.; Korotaev, S.; Orekhova, D.; Scshors, Y.; Tereshchenko, E.; Tereshchenko, P.; Trofimov, I.

    2012-12-01

    The talk is devoted to a natural experiment conducted in Kola Bay off the Barents Sea in which new, six- component electromagnetic seafloor receivers were tested. Signals from a powerful, remote SLW transmitter at several frequencies on the order of tens Hz were recorded at the six sites along a profile across Kola Bay. In spite of the fact that, for technical reasons, not all the components were successfully recorded at every site, the quality of the experimental data was quite satisfactory. The experiment resulted in the successful simulation of an electromagnetic field by the integral equation method. An initial geoelectric model reflecting the main features of the regional geology produced field values that differed greatly from the experimental ones. However, step-by-step modification of the original model considerably improved the fit of the fields. This allowed to correct some features of the regional geology, the fault tectonics in particular. These preliminary results open the possibility of inverse problem solving with more reliable geological conclusions.

  9. The alkaline and alkaline-carbonatite magmatism from Southern Brazil

    NASA Astrophysics Data System (ADS)

    Ruberti, E.; Gomes, C. D. B.; Comin-Chiaramonti, P.

    2015-12-01

    Early to Late Cretaceous lasting to Paleocene alkaline magmatism from southern Brazil is found associated with major extensional structural features in and around the Paraná Basin and grouped into various provinces on the basis of several data. Magmatism is variable in size, mode of occurrence and composition. The alkaline rocks are dominantly potassic, a few occurrences showing sodic affinity. The more abundant silicate rocks are evolved undersaturated to saturated in silica syenites, displaying large variation in igneous forms. Less evolved types are restricted to subvolcanic environments and outcrops of effusive suites occur rarely. Cumulatic mafic and ultramafic rock types are very common, particularly in the alkali-carbonatitic complexes. Carbonatite bodies are represented by Ca-carbonatites and Mg-carbonatites and more scarcely by Fe-carbonatites. Available radiometric ages for the alkaline rocks fit on three main chronological groups: around 130 Ma, subcoveal with the Early Cretaceous flood tholeiites of the Paraná Basin, 100-110 Ma and 80-90 Ma (Late Cretaceous). The alkaline magmatism also extends into Paleocene times, as indicated by ages from some volcanic lavas. Geochemically, alkaline potassic and sodic rock types are distinguished by their negative and positive Nb-Ta anomalies, respectively. Negative spikes in Nb-Ta are also a feature common to the associated tholeiitic rocks. Sr-Nd-Pb systematics confirm the contribution of both HIMU and EMI mantle components in the formation of the alkaline rocks. Notably, Early and Late Cretaceous carbonatites have the same isotopic Sr-Nd initial ratios of the associated alkaline rocks. C-O isotopic Sr-Nd isotopic ratios indicate typical mantle signature for some carbonatites and the influence of post-magmatic processes in others. Immiscibility of liquids of phonolitic composition, derived from mafic alkaline parental magmas, has been responsible for the origin of the carbonatites. Close association of alkaline

  10. Reconstruction of mid-crustal pluton assembly and evolution using trace elements in augite: Sausfjellet pluton, Bindal batholith, north-central Norway.

    NASA Astrophysics Data System (ADS)

    Coint, Nolwenn; Barnes, Calvin; Yoshinobu, Aaron; Prestvik, Tore; Barnes, Melanie

    2013-04-01

    The Sausfjellet pluton is a 445 Ma gabbroic to monzonitic body of 7 Km in diameter emplaced in two stages at ~700 MPa pressure. Stage 1 is a coarse pyroxene hornblende gabbro. Stage 2 intrudes a steep contact between marbles on the east and pelitic migmatites on the west. Stage 2 displays a gradational transition from hornblende biotite two-pyroxene diorite to hornblende biotite three-pyroxene quartz monzonite. This transition is accompanied by a decrease in the An content of normally-zoned plagioclase from An61 to An27. Much of the pluton consists of cumulate rocks, as illustrated by the presence of anorthosite and pyroxene-rich layers. In the western part of the intrusion, hosted by metapelitic rocks, incompatible element concentrations and bulk-rock ^18O increase to levels that cannot be explained by fractional crystallization. These increases were originally explained by AFC processes, but because of the cumulative nature of the rocks, it is difficult to assess magmatic processes using bulk rock compositions. Therefore, we analyzed trace element contents and core-to-rim zoning in augite as a proxy to track changes in melt composition. Augite is normally zoned, with lower incompatible element abundances in the cores than in the rims, consistent with evolution of the melt by fractional crystallization. However, instead of plotting along a single differentiation trend, augite compositions define two trends, which is inconsistent with a closed system. The most mafic rocks define a trend with lower REE contents and smaller (negative) Eu anomalies compared to those from the more evolved part of the pluton, although the two trends overlap in Zr content. The two trends correspond to the central, more mafic zone that intrudes marble and the western, more evolved zone that intrudes metapelites. The trend associated with the western zone consists of the same samples that show bulk-rock ^18O enrichment, and is best explained as resulting from assimilation of the host

  11. Field Guide to Plutonic and Metamorphic Rocks. Earth Science Curriculum Project Pamphlet Series PS-5.

    ERIC Educational Resources Information Center

    Romey, William D.

    Suggested are methods for the collection of field evidence about processes that form plutonic and metamorphic rock. Description and discussion of these types of rocks are provided. The planning and execution of a successful field trip is discussed. Advanced field projects are also discussed. Included are five appendices, references, and a…

  12. Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile

    NASA Astrophysics Data System (ADS)

    Somoza, R.; Tomlinson, A. J.; Zaffarana, C. B.; Singer, S. E.; Puigdomenech Negre, C. G.; Raposo, M. I. B.; Dilles, J. H.

    2015-07-01

    A paleomagnetic and AMS study on Eocene plutonic complexes in the Calama area, northern Chile, reveals high-temperature, high-coercivity magnetizations of dominantly thermoremanent origin and magnetic fabrics controlled by magnetite. The paleomagnetic results indicate that ~ 43 Ma plutons underwent clockwise tectonic rotation, whereas adjacent ~ 39 Ma plutons did not undergo discernible rotation. This points to a middle Eocene age for the younger tectonic rotations associated with the Central Andean Rotation Pattern in the Chuquicamata-Calama area. The petrofabric in these rocks formed under conditions ranging from purely magmatic (i.e. before full crystallization) to low-temperature solid-state deformation. AMS and paleomagnetism suggest that the plutonic bodies were formed by progressive amalgamation of subvertical magma sheets spanning multiple magnetic polarity chrons. The parallelism between magmatic and tectonic foliations suggests that regional tectonic stress controlled ascent, emplacement and rock deformation during cooling. In this context, we suggest that magma ascent and emplacement in the upper crust likely exploited Mesozoic structures which were locally reactivated in the Eocene.

  13. Ar/Ar age data of muscovite from the Keivy Terrane (central Kola Peninsula, arctic European Russia) imply a prolonged fluid-assisted recrystallisation

    NASA Astrophysics Data System (ADS)

    de Jong, K.; Ruffet, G.; Marker, M.

    2012-04-01

    Single grain muscovite 40Ar/39Ar age data from metasediments of the Keivy Terrane point to a prolonged recrystallisation, and imply that the younger age set in metamorphic terranes with a long history cannot always be simply interpreted as due to late and slow cooling. The Keivy terrane is an element of the Palaeoproterozoic Lapland-Kola collisional belt developed along the northern margin of the Fennoscandian (Baltic) Shield. It comprises a lower series of late Archaean meta-volcanic rocks, intruded by earliest Palaeoproterozoic alkali granites that are covered by strongly deformed quartz-rich kyanite-staurolite-garnet-micaschists of the Keivy unit that have yielded magmatic zircons as young as ~2.35 Ga, which were derived from the substratum's alkaline granite. 40Ar/39Ar step-heating dating with a defocussed laser beam of muscovite grains from seven metasediments of the Keivy unit yielded saddle-shaped age spectra in most experiments. In five out of seven cases the base of the saddle corresponded to a plateau age in the range of 1667 to 1593 Ma (60-90% of the gas release; 1 sigma errors: 1.0-1.2 Ma). We do not simply interpret these 40Ar/39Ar ages in the classical way as due to cooling, because the saddle shape of the spectra enables a more complete and detailed interpretation. Saddle-shaped age spectra may result from the presence of different argon reservoirs in partially recrystallised and chemically distinct micas that degas over a different energy interval: a primary, not recrystallised or inherited domain (low and high temperature steps) and a newly formed or recrystallised one (saddle minimum in the intermediate steps). The younger subdomains formed by growth or recrystallisation could characterise the last isotopic record during an extended (re)crystallisation history. It is striking that 1612 and 1615 Ma saddle minimum ages in two samples correspond to a plateau age of 1612 Ma in another sample. Also elevated high and/or low temperature apparent ages of

  14. Insights Into the Formation of Rhyolite From the Searchlight Pluton: Evidence from Oriented Quartz Clusters

    NASA Astrophysics Data System (ADS)

    Froemming, N.; Deering, C. D.; Beane, R. J.; Bachmann, O.

    2012-12-01

    The Miocene Searchlight pluton (SLP) in the Colorado River extensional corridor of southern Nevada, is well-exposed and tilted near-vertical for exceptional cross-sectional study of magma reservoir dynamics and crystal fractionation of a mid- to upper-crustal pluton (3 to 13 km depth). The upper quartz monzonite section is dominated by minerals in apparent random orientation with a medium- to fine-grained texture due to direct contact with the cold host rock. The middle granitic section is dominated by coarse-grained quartz and feldspar, and interpreted to be a zone of extracted liquid from an intermediate magma. The lower monzonite section is composed of coarse-grained plagioclase and potassium feldspar. We used the crystallographic orientations of quartz clusters, as determined by Electron Backscatter Diffraction (EBSD), to test for crystal accumulation in the SLP. Clusters of quartz crystals with matched dipyramidal faces (parallel or Esterel twin orientation) may indicate a period of crystal accumulation. By analyzing representative samples from each section of the pluton, we found that the lower section (intermediate cumulate) and upper section (crystallization front) do not have quartz clusters with matched dipyramidal faces. Although plagioclase grains are aligned in the lower section, the late crystallization of quartz appears to have prevented aligned or preferred growth orientations. In contrast, the middle section has a high percentage of quartz clusters with matched dipyramidal faces - similar to that found in granite porphyry of the Vinalhaven pluton, Maine. The aligned grains may have formed by fractional crystallization, compaction and synneusis of the early forming quartz in this granitic section. We interpret the middle section of the Searchlight pluton as being similar to shallow, upper crustal plutons (3-8 km depth) such as Vinalhaven pluton. The deep vertical exposure of the SLP, shows that the middle section was formed from periodic episodes of

  15. Magnetic fabrics and their relationship with the emplacement of the Piracaia pluton, SE Brazil

    NASA Astrophysics Data System (ADS)

    Raposo, M. Irene B.; Pressi, Leonardo Frederico; de Assis Janasi, Valdecir

    2012-04-01

    Magnetic fabric and rock-magnetism studies were performed on the four units of the 578 ± 3-Ma-old Piracaia pluton (NW of São Paulo State, southern Brazil). This intrusion is roughly elliptical (~32 km2), composed of (i) coarse-grained monzodiorite (MZD-c), (ii) fine-grained monzodiorite (MZD-f), which is predominant in the pluton, (iii) monzonite heterogeneous (MZN-het), and (iv) quartz syenite (Qz-Sy). Magnetic fabrics were determined by applying both anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). The two fabrics are coaxial. The parallelism between AMS and AARM tensors excludes the presence of a single domain (SD) effect on the AMS fabric of the units. Several rock-magnetism experiments performed in one specimen from each sampled units show that for all of them, the magnetic susceptibility and magnetic fabrics are carried by magnetite grains, which was also observed in the thin sections. Foliations and lineations in the units were successfully determined by applying magnetic methods. Most of the magnetic foliations are steeply dipping or vertical in all units and are roughly parallel to the foliation measured in the field and in the country rocks. In contrast, the magnetic lineations present mostly low plunges for the whole pluton. However, for eight sites, they are steep up to vertical. Thin-section analyses show that rocks from the Piracaia pluton were affected by the regional strain during and after emplacement since magmatic foliation evolves to solid-state fabric in the north of the pluton, indicating that magnetic fabrics in this area of the pluton are related to this strain. Otherwise, the lack of solid-state deformation at outcrop scale and in thin sections precludes deformation in the SW of the pluton. This evidence allows us to interpret the observed magnetic fabrics as primary in origin (magmatic) acquired when the rocks were solidified as a result of magma flow, in which steeply

  16. [Impact of industrial pollution on emission of carbon dioxide by soils in the Kola Subarctic Region].

    PubMed

    Koptsik, G N; Kadulin, M S; Zakharova, A I

    2015-01-01

    Soil emission of carbon dioxide, the key component of carbon cycle and the characteristic of soil biological activity, has been studied in background and polluted ecosystems in the Kola subarctic, the large industrial region of Russia. Long-term air pollution by emissions of "Pechenganikel" smelter, the largest source of sulphur dioxide and heavy metals in Northern Europe, has caused the technogenic digression of forest ecosystems. As a result of the digression, the tree layer was destructed, the number of plant species was diminished, the activity of soil biota was weakened, the soils were polluted and exhausted, biogeochemical cycles of elements were disturbed and productivity of ecosystems shrunk. Field investigations revealed the decrease of the in.situ soil respiration in average from 190-230 mg C-CO2/m2 x per h in background pine forests to 130-160, 100, and 20 mg C-CO2/m2.per h at the stages of pine defoliation, sparse pine forest and technogenic barrens of the technogenic succession, respectively. The soil respira- tion in birch forests was more intense than in pine forests and tended to decrease from about 290 mg C-CO2/m2 x per h in background forests to 210-220 and 170-190 mg C-CO2/m2 x per h in defoliating forests and technogenic sparse forests, respectively. Due to high spatial variability of soil respiration in both pine and birch forests significant differences from the background level were found only in technogenic sparse forests and barrens. Soil respiration represents total production of carbon dioxide by plant roots and soil microorganisms. The decrease in share of root respiration in the total soil respiration with the rise of pollution from 38-57% in background forests up to zero in technogenic barrens has been revealed for the first time for this region. This indicates that plants seem to be more sensitive to pollution as compared to relatively resistant microorganisms. Soil respiration and the contribution of roots to the total respiration

  17. Detection and Analysis of Near-Surface Explosions on the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Gibbons, Steven J.; Ringdal, Frode

    2010-05-01

    Seismic and infrasonic observations of signals from a sequence of near-surface explosions at a site on the Kola Peninsula have been analyzed. NORSAR's automatic network processing of these events shows a significant scatter in the location estimates and, to improve the automatic classification of the events, we have performed full waveform cross-correlation on the data set. Although the signals from the different events share many characteristics, the waveforms do not exhibit a ripple-for-ripple correspondence and cross-correlation does not result in the classic delta-function indicative of repeating signals. Using recordings from the ARCES seismic array (250 km W of the events), we find that a correlation detector on a single channel or three-component station would not be able to detect subsequent events from this source without an unacceptable false alarm rate. However, performing the correlation on each channel of the full ARCES array, and stacking the resulting traces, generates a correlation detection statistic with a suppressed background level which is exceeded by many times its standard deviation on only very few occasions. Performing f- k analysis on the individual correlation coefficient traces, and rejecting detections indicating a non-zero slowness vector, results in a detection list with essentially no false alarms. Applying the algorithm to 8 years of continuous ARCES data identified over 350 events which we confidently assign to this sequence. The large event population provides additional confidence in relative travel-time estimates and this, together with the occurrence of many events between 2002 and 2004 when a temporary network was deployed in the region, reduces the variability in location estimates. The best seismic location estimate, incorporating phase information for many hundreds of events, is consistent with backazimuth measurements for infrasound arrivals at several stations at regional distances. At Lycksele, 800 km SW of the events

  18. Trace Elements in the Section of the Kievey PGE Deposit (Kola Peninsula, Russia)

    NASA Astrophysics Data System (ADS)

    Groshev, Nikolay; Rundkvist, Tatyana; Korchagin, Alexey

    2015-04-01

    The Kievey reef-type PGE deposit located in the Lower Layered Horizon (LLH) of the West-Pana intrusion was formed as a result of one or several additional magma injections (Korchagin & Mitrofanov, 2010). The composition of the magma was essentially similar to the saturated tholeiite basalt assumed to be a parental magma for the West-Pana layered intrusion in the Kola Peninsula (Latypov & Chistyakova, 2000). In the present study, whole-rock and ICP-MS trace-element data through a detailed borehole section (37 samples) of the LLH were obtained in an attempt to find some differences in the composition of the magmas. The section of the LLH includes four rhythmical units with a total thickness of 21.5 m lying on the mesocratic gabbronorite containing rare 5-cm interlayers of leucocratic rocks. The bottom of the first cycle is a layer of fine- to medium grained melanorite. Interlayering of gabbronorites and leucogabbronorites is observed in the middle of the cycle. Mottled rock of leucogabbronorite-anorthositic composition with relatively distinct spots caused by amphibolization and saussuritization occurs at the upper leucocratic part of the unit. In comparison to the first cycle of the LLH, the upper cycles are thinner and have more simple internal structures. Well-expressed thin layering is rare, and a mottled structure is weakly developed. Relatively thin (15-55 cm thick) coarse grained olivine melanorite layers at the base of these units are a characteristic feature. The overlying unit is represented by homogeneous fine-medium grained gabbronorites with rare interlayers of coarse and medium grained varieties. PGE mineralization (3 levels about 4-6 ppm Pt+Pd+Au) in the LLH occurs near the lower margins of the upper cycles and is associated with interstitial irregular disseminated sulfides (up to 0.5 vol. % of pentlandite, chalcopyrite and pyrrhotite). Disseminated sulfides are most abundant in the upper part of the first cycle, whereas they are hardly visible in the

  19. Petrogenesis of the Barcroft pluton, northern White-Inyo Mountains, east-central California

    NASA Astrophysics Data System (ADS)

    Ernst, W. G.

    2013-03-01

    The White-Inyo Range lies within the regional transition from Paleozoic-Precambrian North American continental basement to outboard Mesozoic and younger accreted terranes and a superimposed Andean-type arc. In the central White Mountains, the metaluminous Barcroft granodiorite invaded a major NE-striking, SE-dipping high-angle reverse fault—the Barcroft break. Because it is a relatively isolated igneous body and is well exposed over an elevation range of 1,500-4,000 m, its thermal history and that of the surrounding superjacent section are clearer than those of nearly coeval, crowded plutons emplaced in the hotter Sierra Nevada belt. The Barcroft pluton was emplaced as a compositionally heterogeneous series of areally scattered melt pulses episodically injected over the approximate interval 167-161 Ma. The oldest dated rocks are relatively quartzofeldspathic, whereas the youngest is more ferromagnesian, suggesting progressive partial fusion of a relatively mafic protolith. Heavy rare earth-enriched zircons indicate that Barcroft melts were derived at mid-crustal depths from a previously emplaced metabasaltic protolith containing plagioclase but lacking garnet. Granodioritic magma genesis involved the possible mixing of mafic and felsic melts, as well as very minor assimilation of country rocks, but mainly by fractional fusion and crystallization. Bulk chemical, rare earth, and isotopic data suggest that analyzed Barcroft rocks are members of a single suite. Granodioritic rocks are slightly more magnetite-rich at higher elevations on the NE, nearer the roof of the pluton. Earlier thermobarometry chronicled cooling and re-equilibration of the Barcroft pluton from its margins inward, as well as from mid-crustal generation depths of ~25 km through ascent and stalling at ~10-12 km. Refractory phase assemblages crystallized along the pluton margins, whereas subsolidus minerals in the interior of the of body continued to exchange with upper crustal deuteric and

  20. Seychelles alkaline suite records the culmination of Deccan Traps continental flood volcanism

    NASA Astrophysics Data System (ADS)

    Owen-Smith, T. M.; Ashwal, L. D.; Torsvik, T. H.; Ganerød, M.; Nebel, O.; Webb, S. J.; Werner, S. C.

    2013-12-01

    Silhouette and North Islands in the Seychelles represent an alkaline plutonic-volcanic complex, dated at 63 to 63.5 Ma by U-Pb zircon and 40Ar/39Ar methods. This magmatism coincides with the final stages of the cataclysmic Deccan Traps continental flood volcanism in India (67 to 63 Ma), and thus a causal link has been suggested. Recent reconstructions have placed the Seychelles islands adjacent to the Laxmi Ridge and at the western margin of the Réunion mantle plume at the time of formation of the complex. Here we present geochemical evidence in support of the notion that the Seychelles alkaline magmatism was initiated by the peripheral activity of the Réunion mantle plume and is thus part of the Deccan magmatic event. Positive εNd (0.59 to 3.76) and εHf (0.82 to 6.79) and initial Sr of 0.703507 to 0.705643 at 65 Ma indicate derivation of the Seychelles alkaline magmas from a Réunion-like mantle source with an additional minor enriched component, suggesting entrainment of sub-continental lithospheric mantle. The similarity in trace element composition between the Seychelles suite and Deccan alkaline felsic and mafic rocks provides additional evidence for a common mantle source for the Seychelles and Deccan magmatism. Furthermore, we demonstrate the role of fractional crystallisation in the evolution of the alkaline suite. Modelling using major elements suggests that fractional crystallisation and varying degrees of accumulation of olivine, plagioclase, ilmenite, clinopyroxene, alkali feldspar and apatite can describe the spectrum of rock types, from gabbro, through syenite, to granite.

  1. Rapid Intradeformational Emplacement of the Big Hole Canyon Pluton Into the Sevier Fold-Thrust Belt, Southwest Montana.

    NASA Astrophysics Data System (ADS)

    Hespenheide, M. A.

    2002-12-01

    The Big Hole Canyon pluton (BHCp) is a Late Cretaceous pluton emplaced within the Sevier fold-and-thrust belt of the western North American Cordillera. The pluton is exposed over 60km2 and a thickness of ~1400m. Combined anisotropy of magnetic susceptibility (AMS), structural, and field studies document a clear pattern of magmatic flow radiating from at least three subvertical conduits <100m wide and ~300 to ~800m long. Interpreted flow plunges change rapidly to subhorizontal fabrics across the rest of the pluton, matching the expected pattern for laccolithic emplacement. Ascent conduits within the Big Hole Canyon pluton are coincident with the fold axis of an anticline above a thrust ramp, suggesting that the magma ascended up the fault of the fault-bend-fold. Geobarometry and stratigraphic reconstructions indicate an emplacement depth of approximately ~3km. Preliminary thermal modeling indicates that the BHCp was emplaced in 250,000 years, likely between periods of regional shortening deformation. Rapid magma ascent rates calculated by dike flow modeling and implied by entrained wall-rock xenoliths may indicate sequential magma injection into the pluton; an absence of chill margins between phases within the pluton indicates that sequential injections must have taken place quickly enough that the magmas did not have time to cool below the solidus temperature. The geometry and location of the BHCp suggest that magma used a pre-existing fault as a mechanical discontinuity for both ascent and emplacement. Continued intrusion of magma had a sufficient amount of driving pressure to stretch, shear, and lift the roof of the pluton. Detailed field mapping, structural studies, AMS, and thermobarometry indicate that the Late Cretaceous Big Hole Canyon pluton was emplaced as a laccolith at the top of a pre-existing fault-bend-fold in the frontal portion of the Sevier fold-thrust belt.

  2. Numerical modeling of forceful pluton emplacement and associated deformation at different crustal levels - instantaneous, continuous or episodic intrusion?

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Nabelek, P. I.

    2015-12-01

    The Papoose Flat pluton in the White-Inyo Range, California, is one of the best examples of forceful magma emplacement at mid-crustal levels that is revealed by a highly strained aureole. A thermo-rheological 2-D model of the pluton and its aureole is proposed. We explored how the frequency of magma input, from instantaneous to continuous to the bottom of the laccolith, affects the ductile width of the aureole and the crystallinity of the pluton, which has implications for eruption of magma. We modeled these aspects at mid- and upper-crustal levels. The pluton was assumed to be 5 km thick in the middle and 13 km wide. Except for instantaneous growth, pluton was assumed to grow over 5 m.y. The aureole was assumed to have power-law rheology of quartz with dependence on H2O fugacity, which was calculated using the CORK equation (Holland & Powell, 1991) Our result shows that the bottom of the Papoose Flat pluton was emplaced at the brittle-ductile transition zone of the crust. The crustal rheology profile assisted the softening of rocks around the pluton. The simulated temperature and strength profiles confirm that ductile deformation was related to thermal weakening (Saint-Blanquat et al., 2001). Results of incremental growth calculations show that the pluton remains hot and only partially crystalline for millions of years when it grows by frequent input of small batches of liquid. At the mid-crustal level, the ductile region around the pluton is much wider and exists longer than at the shallow crustal level. Brittle rheology is dominant during the late stage growth at the shallow depth. When the pluton grows instantly or by only few episodes of large batches of input, the mobile part of the pluton is thin and the ductile aureole is narrower. High-frequency incremental growth by smaller magma batches produces a large volume of mobile magma that has the potential to induce internal magmatic layering that may be reflected in aligned acquired magnetic susceptibility (AMS

  3. Apatite trace element and halogen compositions as petrogenetic-metallogenic indicators: Examples from four granite plutons in the Sanjiang region, SW China

    NASA Astrophysics Data System (ADS)

    Pan, Li-Chuan; Hu, Rui-Zhong; Wang, Xin-Song; Bi, Xian-Wu; Zhu, Jing-Jing; Li, Chusi

    2016-06-01

    The abundances of trace elements including Sr, Ga and rare earth elements (REE) and halogens in apatite crystals from four intermediate-felsic plutons in the Zhongdian terrane in the Sanjiang region have been determined using electron microprobe and laser ablation inductively coupled plasma mass spectrometry to evaluate the potential of apatite as a petrogenic-metallogenic indicator. The selected plutons include one that is not mineralized (the Triassic Xiuwacu pluton, or the TXWC pluton), one that hosts a porphyry-type Cu deposit (the Pulang pluton, or the PL pluton), one that hosts a porphyry-type Mo deposit (the Tongchanggou pluton, or the TCG pluton), and one that hosts a vein-type Mo deposit (the Cretaceous Xiuwacu pluton, or the CXWC pluton). Except for the CXWC pluton, the other three plutons have adakite-like trace element signatures in whole rocks. The results from this study show that REE, Sr and halogens in apatite can be used to track magma compositions, oxidation states and crystallization history. Apatite crystals from the adakite-like plutons are characterized by much higher Sr/Y and δEu than the non-adakite-type pluton. This means that apatite, which is not susceptible to alteration, is a useful tool for identifying the adakite-like plutons that no longer preserve the initial Sr/Y ratios in whole rocks due to weathering and hydrothermal alteration. Based on apatite Ga contents and δEu values, it is inferred that the parental magmas for the two adakite-like plutons containing porphyry-type Cu and Mo mineralization are more oxidized than that for the non-adakite-type pluton containing vein-type Mo mineralization. Apatite crystals from the vein-type Mo deposit have much lower Cl/F ratios than those from the porphyry-type Cu and Mo deposits. Apatite crystals from the adakite-like pluton without Cu or Mo mineralization is characterized by much lower Cl/F ratios than those from the adakite-like plutons that host the porphyry-type Cu and Mo deposits. The

  4. Geochemical and isotopic (Sr, C, O) data from the alkaline complex of Grønnedal-ĺka (South Greenland): evidence for unmixing and crustal contamination

    NASA Astrophysics Data System (ADS)

    Taubald, H.; Morteani, G.; Satir, M.

    The alkaline intrusion of Grønnedal-ĺka (South Greenland) is the oldest of the ten major rift-related plutonic complexes of southern Greenland that intruded during the Gardar period between 1330 and 1150 Ma into the 2.6-Ga-old gneisses and metasediments of the Ketilidian basement. The Grønnedal-ĺka alkaline intrusion consists of carbonatites, silicocarbonatites, transitional carbonatites and nepheline-bearing syenites. The silicocarbonatites exhibit locally ocellar textures that are typical for immiscibility processes. A 87Sr/86Sr initial ratio of about 0.703184 major and trace element compositions-including REE and C-, and O-isotope data from 15 carbonatite, 12 silicocarbonatite, 10 transitional carbonatite and 8 syenite and samples-provide evidence for minor crustal contamination of the mantle-derived magma that generated by unmixing carbonatites, silicocarbonatites and syenites. A scatter in major and trace element contents and isotope ratios is related to late- to post-magmatic alteration processes. The Grønnedal-ĺka silicocarbonatites are one of the rather rare cases in which unmixing of a highly alkaline mantle-derived magma into an alkalisilicate and a carbonatitic magma-fraction under plutonic conditions is well documented by textural and geochemical data.

  5. Cryogenian alkaline magmatism in the Southern Granulite Terrane, India: Petrology, geochemistry, zircon U-Pb ages and Lu-Hf isotopes

    NASA Astrophysics Data System (ADS)

    Santosh, M.; Yang, Qiong-Yan; Ram Mohan, M.; Tsunogae, T.; Shaji, E.; Satyanarayanan, M.

    2014-11-01

    The Southern Granulite Terrane (SGT) in India preserves the records of the formation and recycling of continental crust from Mesoarchean through Paleoproterozoic to Neoproterozoic and Cambrian, involving multiple subduction-accretion-collision associated with major orogenic cycles. A chain of unmetamorphosed and undeformed alkaline magmatic intrusions occurs along the northern margin of the SGT aligned along paleo-suture zones. Here we investigate two representative plutons from this suite, the Angadimogar syenite (AM) and the Peralimala alkali granite (PM) through field, petrological, geochemical, zircon U-Pb and Lu-Hf studies. Magma mixing and mingling textures and mineral assemblages typical of alkaline rocks are displayed by these plutons. The whole-rock major and trace element data characterize their alkaline nature. In trace element discrimination diagrams, the AM rocks straddle between the VAG (volcanic-arc granites) and WPG (within plate granites) fields with most of the samples confined to the VAG field, whereas the PM rocks are essentially confined to the WPG field. The diversity in some of the geochemical features between the two plutons is interpreted to be the reflection of source heterogeneities. Most zircon grains from the AM and PM plutons display oscillatory zoning typical of magmatic crystallization although some grains, particularly those from the PM pluton, show core-rim structures with dark patchy zoned cores surrounded by irregular thin rims resulting from fluid alteration. The weighted mean 206Pb/238U ages of the magmatic zircons from three samples of the AM syenite are in the range of 781.8 ± 3.8 Ma to 798 ± 3.6 Ma and those from two samples of the PM alkali granite yield ages of 797.5 ± 3.7 Ma and 799 ± 6.2 Ma. A mafic magmatic enclave from the AM pluton shows weighted mean 206Pb/238U age of 795 ± 3.3 Ma. The AM and PM plutons also carry rare xeneocrystic zircons which define upper intercept concordia ages of 3293 ± 13 Ma and 2530

  6. The Granite Aqueduct and Advection of Water and Heat Through Plutonic Terranes

    NASA Astrophysics Data System (ADS)

    Glazner, A. F.; Bartley, J. M.; Law, B.; Coleman, D. S.

    2011-12-01

    Although water plays a critical role in the genesis and movement of magma, it is largely lost from rocks upon crystallization. Observation of active volcanoes, analysis of magmatic inclusions, and experimental petrology indicate that intermediate magmas in subduction zones are water-rich, containing 5 wt% or more H2O. Carmichael (2002) wrote of the "andesite aqueduct" that conveys copious amounts of water from magma source regions in subduction zones to the surface and atmosphere. We suggest that this water plays a significant role in the thermal and textural history of the plutonic rocks through which it passes. A dacite magma with 5 wt% H2O crystallizes to granodiorite with ~0.5 wt% H2O, releasing >100 kg of H2O per m3. Field and geochronological data indicate that many sheet-like plutons are constructed from the top down, typically over 1 m.y. or more, likely bathing earlier pulses in ascending water released from later pulses. For a 5 km thick pluton, this release amounts to a condensed-water equivalent depth of ~500 m per unit of horizontal area, a truly vast amount. Plutons preserve abundant evidence for late-stage fluid transfer via a "granite aqueduct." For example, the Tuolumne Intrusive Suite of California is cut by myriad hydrothermally altered pipes that are typically found within or near aplite-pegmatite dikes (Mustart & Horrigan, 2000). The pipes attest to focused fluid flow, and the dikes themselves are the crystallized remnants of late-stage magmatic liquids. Upward advection of heat through dikes and pipes transfers thermal energy from newly crystallizing magma increments to older ones above much more efficiently and rapidly than thermal conduction, and could account for the widespread and profound recrystallization that produces the large grain size and low-temperature mineral assemblages of many granitic rocks. Although the concept that plutons represent the frozen record of huge, highly liquid magma chambers is losing favor, some recent studies

  7. Distribution of fluid inclusions in igneous quartz of the Capitan pluton, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Ratajeski, Kent; Campbell, Andrew R.

    1994-02-01

    Fluid inclusions in granites have been used extensively in studies of magmatic-hydrothermal processes, but few studies have documented the distribution of secondary fluid inclusions within the nonmineralized main body of an intrusion. Previous work on fluid inclusions in Th-U-REE quartz/ fluorite vein deposits in the Capitan pluton suggests that these veins resulted from high-temperature, high-salinity, magmatic fluids in fractured and brecciated zones in the cooled outer carapace of the pluton. Petrographic examination of phenocryst quartz in forty-four thin sections of granite from the Capitan pluton reveals that these same fluids are found in secondary fluid inclusions. Fluid inclusions with daughter minerals commonly occur in the outer granophyre and aplite zones, but are usually absent in the porphyritic core. Microthermometric data and calculated salinities from fifty-eight fluid inclusions in phenocryst quartz and thirty-one fluid inclusions in miarolitic quartz (both samples taken from the granophyre zone) also correlate fairly well with the data from the Th-U-REE quartz/fluorite vein deposits, and similar types of fluid inclusions are found in all three occurrences of quartz. A major difference, however, is that vapor-rich inclusions, abundant as secondary inclusions in igneous phenocryst quartz, are extremely scarce in the vein quartz. Liquid-vapor homogenization temperatures of high-salinity inclusions in phenocryst quartz range from 204-509°C with an average of 384°C. Halite dissolution temperatures of high salinity inclusions range from 442-583°C with an average of 525°C. Total homogenization temperatures are not as well documented due to decrepitation of many of the high salinity inclusions before total homogenization. Samples of miarolitic quartz appear to contain more low-salinity fluid inclusions than the phenocryst quartz, but high-salinity inclusions are present as well. These observations suggest that the magmatic-hydrothermal fluids

  8. Genesis and evolution of water in a two-mica pluton: A hydrogen isotope study

    USGS Publications Warehouse

    Brigham, R.H.; O'Neil, J.R.

    1985-01-01

    Measurements were made of the hydrogen isotope composition of 74 samples of muscovite, biotite, vein quartz and whole rocks from the Papoose Flat pluton, eastern California, U.S.A., and adjacent metamorphic and sedimentary rocks in order to elucidate the genesis and evolution of water and hydrous minerals in a two-mica granodiorite. Electron microprobe analyses were made of all micas so that the Suzuoki-Epstein equation could be used in evaluating the data. Based on experimental, theoretical and textural evidence of mica paragenesis, a model of hydrogen isotope fractionation between an aqueous vapor and a magma during crystallization has been constructed. This model accounts for the observed hydrogen isotope relations and implies that primary hydrogen isotope compositions have been preserved in a large portion of the pluton. The ?? D-values of biotites vary widely over the range -103 to -66% with most values lying between -90 and -70??? Muscovites, on the other hand, are isotopically more uniform and have ?? D-values of -61 to -41??? with most values lying between -50 and -46??? These data are consistent with the interpretation that biotite formed over a long period of crystallization whereas muscovite formed in a narrow interval, presumably during the final stages of crystallization when alumina and water contents were at their highest. Only 8 of the 21 muscovite-biotite pairs analyzed are in hydrogen isotope equilibrium as calculated from the Suzuoki-Epstein equation. Biotites in the western half of the pluton have relatively low ?? D-values of around -85???, whereas those in the eastern half have higher values of up to -66??? This pattern is a consequence of a loss of permeability associated with the syn-intrusive deformation of the western margin of the pluton. This loss of permeability enhanced the preservation of primary hydrogen isotope relations there by diverting water evolved from the magma out through the eastern half of the pluton where some deuteric

  9. RECLAMATION OF ALKALINE ASH PILES

    EPA Science Inventory

    The objective of the study was to develop methods for reclaiming ash disposal piles for the ultimate use as agricultural or forest lands. The ashes studied were strongly alkaline and contained considerable amounts of salts and toxic boron. The ashes were produced from burning bit...

  10. Geochemistry and petrogenesis of late Ediacaran (605-580 Ma) post-collisional alkaline rocks from the Katherina ring complex, south Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Azer, M. K.; Obeid, M. A.; Ren, M.

    2014-10-01

    The Katherina ring complex (KRC) in the central part of south Sinai, Egypt, is a typical ring complex of late Neoproterozoic age (605-580 Ma). It was developed during the final tectono-magmatic stage of the north Arabian-Nubian Shield (ANS) during evolution of the Pan-African crust. The KRC includes Katherina volcanics, subvolcanic bodies, ring dykes and Katherina granitic pluton. The Katherina volcanics represent the earliest stage of the KRC, which was subsequently followed by emplacement of the subvolcanic bodies and ring dykes. The Katherina granitic pluton depicts as the latest evolution stage of the KRC that intruded all the early formed rock units in the concerned area. The Katherina volcanics are essentially composed of rhyolites, ignimbrite, volcanic breccia and tuffs. Mineralogically, the peralkaline rhyolites contain sodic amphiboles and aegirine. The rhyolite whole rock chemistry has acmite-normative character. The subvolcanic bodies of the KRC are represented by peralkaline microgranite and porphyritic quartz syenite. The ring dykes are semicircular in shape and consist mainly of quartz syenite, quartz trachyte and trachybasalt rock types. The Katherina subvolcanic rocks, volcanic rocks as well as the ring dykes are alkaline or/and peralkaline in nature. The alkaline granitic pluton forms the inner core of the KRC, including the high mountainous areas of G. Abbas Pasha, G. Bab, G. Katherina and G. Musa. These mountains are made up of alkaline syenogranite and alkali feldspar granite. The mantle signature recorded in the KRC indicates a juvenile ANS crust partial melting process for the generation of this system. The evolution of the KRC rocks is mainly dominated by crystal fractionation and crustal contamination. Mineral geothermometry points to the high temperature character of the KRC, up to 700-1100 °C.

  11. Effectiveness of Gotu Kola Extract 750 mg and 1000 mg Compared with Folic Acid 3 mg in Improving Vascular Cognitive Impairment after Stroke

    PubMed Central

    Wibowo, Samekto

    2016-01-01

    This study aimed to determine the effectiveness of gotu kola (Centella asiatica) in improving cognitive function in patients with vascular cognitive impairment (VCI). This study uses a quasi-experimental design. Subjects in this study were patients with poststroke cognitive impairment who were treated at two hospitals in Yogyakarta, Indonesia. The number of subjects was 48: 17 subjects were treated with 1000 mg/day of gotu kola extract, 17 subjects treated with 750 mg/day of gotu kola extract, and 14 subjects treated with 3 mg/day of folic acid for 6 weeks. A Montreal Cognitive Assessment-Indonesian version (MoCA-Ina) was conducted at the beginning of treatment and after 6 weeks of therapy. It was found that all trials effectively improved poststroke VCI based on MoCA-Ina scores over the course of the study. There is no significant difference in ΔMoCA-Ina (score at the 6th week of treatment − score at the beginning) mean score among the three groups, indicating that gotu kola is as effective as folic acid in improving poststroke VCI. Gotu kola was shown to be more effective than folic acid in improving memory domain. This study suggested that gotu kola extract is effective in improving cognitive function after stroke. PMID:27340413

  12. Acidic Plutonism in the Izu-Ogasawara (Bonin)-Mariana (IBM) Arc and Growth of Arc Crust: Petrological and Geochemical Characteristics of the Tonalite at the Komahashi-Daini Seamount and Difference From the Tanzawa Plutonic Complex

    NASA Astrophysics Data System (ADS)

    Haraguchi, S.; Ishii, T.

    2003-12-01

    Recent seismic refraction and reflection data suggest that the continents are underlain by mafic lower crust and felsic middle crust. Petrogenesis of granitic middle crust layers is important for understanding the formation and evolution of continental crust. In modern tectonic regimes, tonalitic rocks and chemically equivalent volcanic rocks occur in island arcs and active continental margins. Thus, the petrogenesis of tonalite and related rocks in intra-oceanic arc settings is of great importance in understanding the processes of both recent island arc and continental crust formation. The Komahashi-Daini Seamount, in the northern Kyushu-Palau Ridge in the northern Philippine Sea plate, was investigated by the Japanese Geodynamics Project (GDP) cruises in the 1970's, and by the R/V Tansei-maru (Ocean Research Institute, University of Tokyo) in the 1990's. Plutonic rocks were dredged from the seamount, and have great importance for understanding the processes of island arc and continental crust formation. The petrographical and geochemical characteristics of the Komahashi-Daini Seamount tonalite are summarized as follows: (1) These tonalites are classified into biotite-hornblende tonalite and hornblende tonalite. Phenocrysts, especially plagioclase, show common lamellar twins and oscillatory zoning patterns; (2) This tonalite show low content of bulk LILE, and classified into low-K calc-alkaline, 1 to 8 wt.% MgO with 55 to 75 wt.% SiO2; (3) This tonalite shows roughly parallel and increasing total REE content with increasing SiO2 content, except for increasingly strong negative Eu anomaly at higher SiO2. These factors indicate that the Komahashi-Daini Seamount tonalite was produced by fractional crystallization. The parent magma of this tonalite is considered lower than 56 wt.% SiO2. Based on this relationship, we concluded that the source for the parental magma was arc mantle peridotite. We compared these tonalites with typical tonalite, i.e., Tanzawa Complex

  13. Electromagnetic studies on the Kola peninsula and in Northern Finland by means of a powerful controlled source

    NASA Astrophysics Data System (ADS)

    Velikhov, Ye. P.; Zhamaletdinov, A. A.; Belkov, I. V.; Gorbunov, G. I.; Hjelt, S. E.; Lisin, A. S.; Vanyan, L. L.; Zhdanov, M. S.; Demidova, T. A.; Korja, T.; Kirillov, S. K.; Kuksa, Yu. I.; Poltanov, A. Ye.; Tokarev, A. D.; Yevstigneyev, V. V.

    1986-07-01

    Station "Khibiny", equipped with a powerful magnetohydrodynamic (MHD) generator and/or diesel generator, has been successfully used since 1976 to study the electrical conductivity of the Earth's crust in the northern part of the Baltic Shield. The present paper describes the techniques of measurement, data processing and interpretation of the five-component electromagnetic fields created by this source. A longitudinal conductance map for the upper 10 km of the Earth's crust has been constructed. Several blocks, with conductances varying from 0.1 to some thousands of Siemens, have been revealed on the Kola Peninsula, in northern Karelia and in northern Finland. The blocks of high conductance are connected with relatively young complexes of Early Proterozoic and Late Archean ages. In some places, they create thick and extensive conductive belts such as the Imandra-Varzuga and the Pechenga zones. More often, they appear in the shape of vast regions with enhanced conductivity (e.g., the granulite belts and the Allarechen region). The geoelectric cross-section of the Imandra-Varzuga ore-critical structure has been studied in detail, using the method of electromagnetic field migration. Its depth extent is approximately 10 km. Highly resistant blocks are associated with the most ancient geological units, of early Archean age. Resistant regions have been found in the Murmansk and Central Kola regions, as well as in the Kovdor massif and in the Central Finland granite area. These regions are the most promising ones for deep electromagnetic sounding of the lower crust and the upper mantle of the Earth.

  14. Induced seismicity in large-scale mining in the kola peninsula and monitoring to reveal informative precursors

    NASA Astrophysics Data System (ADS)

    Melnikov, N. N.; Kozyrev, A. A.; Panin, V. I.

    1996-07-01

    Large volumes of rock mass, mined-out and moved within these deposits, resulted in irreversible changes in the geodynamic regime in the upper earth's crust of the adjacent territory. These changes manifest themselves in a more frequent occurrence of such intensive dynamic phenomena as tectonic rock bursts due to fault movement adjacent to the area which is mined-out and man-made earthquakes which sharply decrease mining safety and result in great material losses. To develop the prediction techniques of such phenomena, a monitoring system is created, based on the program of the Kola Complex of geodynamic measuring stations. Most of this system is realized in the region of the Khibiny apatite mines. The system provides regional seismological monitoring, local prediction of seismicity in separate areas of a rock mass and, determination of stress and strain in rock masses, local geophysical monitoring over the state of rocks in a rock mass as well as physical and mathematical modelling of geodynamic processes in the upper earth's crust. The investigations have resulted in the distinguishing of some regularities in manifestations of induced seismicity and tectonic rock bursts and in the determination of strain precursors of intensive seismic events in the Khibiny mines. The mechanism is provided by the induced seismicity which resulted from the anthropogenic impact on the geological medium. A geodynamic monitoring complex is described, which is used to reveal the precursors of powerful seismic events in situ, and monitoring results are shown, obtained in the Kola Complex of geodynamic stations. Methods of preventing tectonic rock bursts and induced earthquakes are presented.

  15. Accumulation and distribution of heavy metals in sediments and fish in the Kola Peninsula lakes under airborne contamination

    SciTech Connect

    Dauvalter, V.A.; Kashulin, N.A.; Lukin, A.A.

    1996-12-31

    The copper-nickel smelter complexes of Kola Peninsula are powerful sources of atmospheric contamination by heavy metals (Ni, Cu, Co, Cd, etc.) and acidic oxides (SO{sub 2}) deposited in precipitation and caused negative effects on local freshwater ecosystems. The rise of background levels occurs over large areas in the region. The aim of the investigations is to assess effects of the air contamination on lake ecosystems at different distances (from 15 to 120 km) from one of the main heavy metal pollution sources of the Kola Peninsula - smelters of the Pechenganickel Company. Negative effects of air pollution by the smelters on the freshwater ecosystems were recorded. Lake sediments accumulate very intensively heavy metals. Heavy metal contamination factors calculated as the quotient of concentration from the uppermost (0-1 cm) sediment to the mean preindustrial background value (concentrations from 20-30 cm sediment layers) for the investigated region reach up 120 for Ni and 76 for Cu in the lakes within a distance of 40 km from the smelters. The lakes in this region have very high contamination degree according classification by Hakanson (1980). Concentrations of Ni in organs and tissues of all studied fishes (whitefish, pike, perch, arctic char, brown trout) were considerably higher in the investigated lakes than in remote unpolluted lakes. There is tight positive correlation between Ni concentrations in surficial sediment (0-1 cm) and fish kidney (r = +0.854), as well as between values of contamination degree and Ni content in fish (r = +0.871).

  16. In Vitro Anti-Listerial Activities of Crude n-Hexane and Aqueous Extracts of Garcinia kola (heckel) Seeds

    PubMed Central

    Penduka, Dambudzo; Okoh, Anthony I.

    2011-01-01

    We assessed the anti-Listerial activities of crude n-hexane and aqueous extracts of Garcinia kola seeds against a panel of 42 Listeria isolates previously isolated from wastewater effluents in the Eastern Cape Province of South Africa and belonging to Listeria monocytogenes, Listeria grayi and Listeria ivanovii species. The n-hexane fraction was active against 45% of the test bacteria with zones of inhibition ranging between 8–17 mm, while the aqueous fraction was active against 29% with zones of inhibition ranging between 8–11 mm. The minimum inhibitory concentrations (MIC) were within the ranges of 0.079–0.625 mg/mL for the n-hexane extract and 10 to >10 mg/mL for the aqueous extract. The rate of kill experiment carried out for the n-hexane extract only, revealed complete elimination of the initial bacterial population for L. grayi (LAL 15) at 3× and 4× MIC after 90 and 60 min; L. monocytogenes (LAL 8) at 3× and 4× MIC after 60 and 15 min; L. ivanovii (LEL 18) at 3× and 4× MIC after 120 and 15 min; L. ivanovii (LEL 30) at 2, 3 and 4× MIC values after 105, 90 and 15 min exposure time respectively. The rate of kill activities were time- and concentration-dependant and the extract proved to be bactericidal as it achieved a more than 3log10 decrease in viable cell counts after 2 h exposure time for all of the four test organisms at 3× and 4× MIC values. The results therefore show the potential presence of anti-Listerial compounds in Garcinia kola seeds that can be exploited in effective anti-Listerial chemotherapy. PMID:22072929

  17. Carboniferous high-potassium I-type granitoid magmatism in the Eastern Pontides: The Gümüşhane pluton (NE Turkey)

    NASA Astrophysics Data System (ADS)

    Topuz, Gültekin; Altherr, Rainer; Siebel, Wolfgang; Schwarz, Winfried H.; Zack, Thomas; Hasözbek, Altuğ; Barth, Mathias; Satır, Muharrem; Şen, Cüneyt

    2010-04-01

    The Gümüşhane pluton, a high-K calc-alkaline I-type granodiorite/granite complex, forms an important component of the pre-Liassic basement of the Eastern Pontides (NE Turkey). In its eastern part, the pluton shows a compositional zonation ranging from biotite-hornblende granodiorite in the NW through biotite-hornblende granite to leucogranite/granophyre in the SE. Numerous mafic microgranular enclaves (up to ˜ 40 cm in diameter) suggest the former presence of globules of mafic melt during crystallization. Emplacement of the pluton occurred during the latest Early Carboniferous, as shown by the 320 ± 4 Ma 40Ar- 39Ar biotite/hornblende and 324 ± 6 Ma LA-ICP-MS U-Pb zircon ages. In Harker diagrams, samples of the different rock types exhibit well-defined data trends. With increasing SiO 2, the abundances of TiO 2, Al 2O 3, Fe 2O 3tot, MnO, MgO, CaO, P 2O 5 and Sc decrease, but those of K 2O and Rb increase. However, the variations of Sr, Ba, (La/Yb) cn, Sr/Y and ∑ REEs vs. SiO 2 form distinctive groupings, which cannot be explained by a simple fractional crystallization. Chondrite-normalized (cn) REE patterns of granodiorite/granite samples show concave-upward shapes with (La/Yb) cn ranging from 5.2 to 12.4 and Eu/Eu* from 0.84 to 0.47, while there is almost no fractionation of the middle REE relative to the heavy REE. In primitive mantle-normalized element concentration diagrams, all rocks display marked negative anomalies in Ba, Nb/Ta, Sr, P and Ti, but positive anomalies in K and Pb. These geochemical features imply a fractionating mineral assemblage of clinopyroxene, amphibole and plagioclase without significant involvement of garnet. The granophyres are, on the other hand, characterized by higher K 2O/Na 2O and Rb/Sr ratios, lower (La/Yb) cn ratios (1.3 to 4.8) and more pronounced negative anomalies in Ba, Nb/Ta, Sr, Eu, P and Ti. Initial ɛNd values range from - 3.78 to - 5.30 and Nd model ages from 1.38 to 163 Ga. The magmas of the granite

  18. Voloshinite, a new rubidium mica from granitic pegmatite of Voron'i Tundras, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Pekov, I. V.; Kononkova, N. N.; Agakhanov, A. A.; Belakovsky, D. I.; Kazantsev, S. S.; Zubkova, N. V.

    2010-12-01

    Voloshinite, a new mineral of the mica group, a rubidium analogue of lepidolite, has been found from the rare-element granitic pegmatite at Mt. Vasin-Myl'k, Voron'i Tundras, Kola Peninsula, Russia. It is closely associated with pollucite and lepidolite and commonly with muscovite, albite, and quartz; K,Rb-feldspar, rubicline, spodumene, montebrasite, and elbaite are among associated minerals as well. Voloshinite, a late mineral that formed after pollucite, commonly fills polymineralic veinlets and pods within the pollucite aggregates. It occurs as rims up to 0.05 mm thick around lepidolite, as intergrowths of tabular crystals up to 0.25 mm in size, and occasionally replaces lepidolite. The new mineral is colorless, transparent, with vitreous luster. Cleavage is eminent parallel to {001}; flakes are flexible. The calculated density is 2.95 g/cm3. The new mineral is biaxial (-), with 2 V = 25°, α calc = 1.511, β = 1.586, and γ = 1.590. The optical orientation is Y = b, Z = a. The chemical composition of the type material determined by electron microprobe (average of five point analyses; Li has been determined with ICP-OES) is as follows (wt %): 0.03 Na2O, 3.70 K2O, 12.18 Rb2O, 2.02 Cs2O, 4.0 Li2O, 0.03 CaO, 0.02 MgO, 0.14 MnO, 21.33 Al2O3, 53.14 SiO2, 6.41 F, -O = F2 2.70, total is 100.30. The empirical formula is: (Rb0.54K0.33Cs0.06)Σ0.93(Al1.42Li1.11Mn0.01)Σ2.54(Si3.68Al0.32)Σ4O10 (F1.40(OH)0.60)Σ2. The idealized formula is as follows: Rb(LiAl1.5□0.5)[Al0.5Si3.5O10]F2. Voloshinite forms a continuous solid solution with lepidolite. According to X-ray single crystal study, voloshinite is monoclinic, space group C2/ c. The unit-cell dimensions are: a = 5.191, b = 9.025, c = 20.40 Å, β = 95.37°, V= 951.5 Å3, Z = 4. Polytype is 2 M 1. The strongest reflections in the X-ray powder diffraction pattern ( d, Å- I[ hkl]) are: 10.1-60[001]; 4.55-80[020, 110, 11 bar 1 ]; 3.49-50[11 bar 4 ]; 3.35-60[024, 006]; 3.02-45[025]; 2.575-100[11 bar 6 , 131, 20 bar 2 , 13

  19. Isolation of alkaline mutagens from complex mixtures

    SciTech Connect

    Ho, C.H.; Guerin, M.R.; Clark, B.R.; Rao, T.K.; Epler, J.L.

    1981-05-01

    A method for the preparative-scale enrichment of alkaline mutagens from complex natural and anthropogenic mixtures is described. Mutagenic alkaline fractions were isolated from cigarette smoke, crude petroleum, and petroleum substitutes derived from coal and shale.

  20. Prehnite in plutonic and metamorphic rocks of the northern Santa Lucia Range, Salinian block, California

    USGS Publications Warehouse

    Ross, Donald C.

    1976-01-01

    Prehnite is abundant as monomineralic veins, as lenses in biotite, and as discrete patches and apparent primary crystals in both plutonic and metamorphic rocks along the west edge of the Salinian block in the northern Santa Lucia Range. The prehnite appears to be concentrated near the Sur fault zone but is very rare in Franciscan rocks west of the fault zone. The prehnite does not appear to have been derived by local alteration of minerals in the country rocks (either plutonic or metamorphic). I suggest that solutions, derived from a "substratum" (possibly Franciscan graywacke) beneath the tectonically thinned west margin of the Salinian block, migrated through the fractured rocks of the Salinian block near the Sur fault zone and that the chemical and physical nature of these rocks favored selective prehnite deposition.

  1. Pennsylvanian pluton stitching of Wrangellia and the Alexander terrane, Wrangell Mountains, Alaska

    SciTech Connect

    Gardner, M.C.; Bergman, S.C.; Cushing, G.W. ); Plafker, G. ); Campbell, R.B.; Dodds, C.J. ); McClelland, W.C. ); Mueller, P.A. ); MacKevett, E.M. Jr.

    1988-11-01

    A quartz monzonite-syenite-alkali granite plutonic complex in eastern Alaska crosscuts the contact of the Alexander terrane and Wrangellia and intrudes the basement rocks of both terranes. Zircon U-Pb data indicate an intrusion age of 309 {plus minus} 5 Ma (Middle Pennsylvanian) for the pluton, and {sup 40}K-{sup 40}Ar age for hornblende separates indicate cooling to about 450 C during Middle Pennsylvanian-Early Permian time. The new field relations and age data demonstrate the Wrangellia and the Alexander terrane were contiguous during the Middle Pennsylvanian. This conclusion provides an important new constraint on paleogeographic reconstructions of the northwest Cordillera, and necessitates reassessment of stratigraphic and paleomagnetic data that were cited as evidence that the terranes evolved separately until the late Mesozoic.

  2. River Valley pluton, Ontario - A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

    NASA Technical Reports Server (NTRS)

    Ashwal, Lewis D.; Wooden, Joseph L.

    1989-01-01

    This paper presents Nd, Sr, and Pb isotopic data indicating a late-Archean/early-Proterozoic age for the River Valley anorthositic pluton of the southwestern Grenville Province of Sudbury, Ontario. Pb-Pb isotopic data on 10 whole-rock samples ranging in composition from anorthosite to gabbro yield an age of 2560 + or - 155 Ma. The River Valley pluton is thus the oldest anorthositic intrusive yet recognized within the Grenville Province. The Sm-Nd isotopic system records an age of 2377 + or - 68 Ma. High Pb-208/Pb-204 of deformed samples relative to igneous-textured rocks implies Th introduction and/or U loss during metamorphism in the River Valley area. Rb-Sr data from igneous-textured and deformed samples and from mineral separates give an age of 2185 + or - 105 Ma, indicating substantial disturbance of the Rb-Sr isotopic system.

  3. An underground characterization program for a nuclear fuel waste disposal vault in plutonic rock

    SciTech Connect

    Thompson, P.M.; Everitt, R.A.

    1993-12-31

    The Canadian Nuclear Fuel Waste Management Program (CNFWMP) is developing a concept for disposing of nuclear fuel waste that involves placing and sealing it in a disposal vault excavated 500 to 1,000 m deep in the stable plutonic rock of the Canadian Shield. In this concept, engineered and natural barriers serve to isolate the waste from the biosphere. Since 1983, underground characterization and testing in support of the CNFWMP has been ongoing at the Underground Research Laboratory (URL) in southeastern Manitoba. This paper draws on experience gained at the URL to recommend an approach to underground characterization that would provide the necessary information to make design decisions for a disposal vault in plutonic rock.

  4. Petrology and U-Pb geochronology of buried Avalonian plutonic rocks on southeastern Cape Cod

    USGS Publications Warehouse

    Leo, G.W.; Mortensen, J.K.; Barreiro, B.; Phillips, J.D.

    1993-01-01

    Plutonic rocks have been intersected by two separate drill holes on souteastern Cape Cod. Hole CC2 is located about 7 km south of the Nauset anomaly, an east-northeast-trending magnetic lineament that was considered to separate the distinct plutonic zones of Avalon terrane. This drill hole intersected weakly foliated, fairly homogeneous biotite granite. Zircons from this granite give a U-Pb age of 584+9/-8 Ma. Hole CC1 is located about 12 km north of the Nauset anomaly. The drill core intersected foliated, sheared, biotite granodiorite and biotite-hornblende-clinopyroxene-quartz gabbro, metamorphosed to greenschist facies. The deformed and altered state of these rocks, as well as their geochemistry, suggest that their origin and possibly their ages are distinct from the granite in hole CC2. No datable zircons were obtained from rocks in CC1. -from Authors

  5. Isotopic studies of the late Archean plutonic rocks of the Wind River Range, Wyoming.

    USGS Publications Warehouse

    Stuckless, J.S.; Hedge, C.E.; Worl, R.G.; Simmons, K.R.; Nkomo, I.T.; Wenner, D.B.

    1985-01-01

    Two late Archaean intrusive events were documented in the Wind River Range by isotopic studies of the Rb-Sr and U-Th-Pb systems in whole-rock samples and the U-Pb systematics for zircon. An age of approx 2630(20) m.y. for the Louis Lake batholith and apparent ages of 2504(40) to 2575(50) m.y. for the Bear Ears pluton were obtained. Post-magmatic hydrothermal events approximately Tertiary in age, lowered delta 18O values and disturbed parent-daughter relationships in most of the isotopic systems investigated. The two intrusive units apparently were derived from different protoliths. Initial isotopic ratios and petrochemistry for the Louis Lake batholith are consistent with an early Archaean trondhjemitic to tonalitic source. The protolith for the Bear Ears pluton must have been subjected to high-grade metamorphism that caused loss of Rb and U prior to magma generation. -L.C.H.

  6. The role of pegmatites and acid fluids for REE/HFSE mobilization in the Strange Lake peralkaline granitic pluton, Canada

    NASA Astrophysics Data System (ADS)

    Gysi, A. P.; Williams-Jones, A.

    2012-12-01

    The Strange Lake pluton in Canada is a mid-Proterozoic peralkaline granitic intrusion that is host to a world-class rare earth element (REE), yttrium (Y) and high-field strength element (HFSE) deposit containing more than 50 Mt ore at >1.5 wt.% REE and >3 wt.% Zr. The highest REE/HFSE concentrations are found in pegmatite-rich zones characterized by intense alteration. Previous studies of Strange Lake and other peralkaline and alkaline intrusions, such as Khan Bogd (Mongolia) and Tamazeght (Morocco) plutons have shown that hydrothermal alteration may play an important role in the mobility of the REE/HFSE. However, the fluid chemistry and conditions of alteration (i.e., P, T, pH, fO2, ligand activity) in these systems still need to be constrained to evaluate the importance and scale of such hydrothermal mobilization. We present new data from the B-zone, a pegmatite-rich zone located in NW Strange Lake. The pegmatites are generally zoned and form two main types. The border-type pegmatites consist of quartz, K-feldspar and hematized aegirine, whereas volatile-rich pegmatites consist of hydrothermal quartz and fluorite. Transitions between both types were also observed, with the K-feldspar being partly altered and replaced by Al-Si-rich phyllosilicates. The heavy (H)REE and Zr were primarily concentrated in zirconosilicates such as elpidite, now pseudomorphed by zircon or gittinsite, whereas light (L)REE and Y were concentrated in REE-F-(CO2)-minerals such as fluocerite and bastnäsite. Textural and mineralogical observations indicate that these minerals are primary and were partly to completely leached upon fluid-rock interaction in the pegmatites. Secondary phases include Ca-F-Y-rich minerals, mainly hydrothermal fluorite, that fill vugs and replaced primary REEHFSE minerals. The presence of hydrothermal fluorite veins, micro-veins, vugs and micro-breccia in the most altered parts of the B-zone are interpreted to reflect interaction of the rocks with a F-rich fluid

  7. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, David B.; Lao, Guifang

    1998-01-01

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium.

  8. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, D.B.; Lao, G.

    1998-01-06

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium. 3 figs.

  9. Potassium-argon and lead-alpha ages of plutonic rocks, Bokan Mountain area, Alaska

    USGS Publications Warehouse

    Lanphere, M.A.; MacKevett, E.M., Jr.; Stern, T.W.

    1964-01-01

    Most of the granitic rocks in the Bokan Mountain area, southeastern Alaska, are early Paleozoic (probably Ordovician) judged by potassium-argon and lead-alpha age measurements. The Bokan Mountain Granite, the youngest intrusive unit in the area, belongs to a Mesozoic plutonic episode. These age measurements are the first direct evidence for the emplacement of early Paleozoic granitic intrusive rocks close to the Pacific margin of North America.

  10. Magmatic and metamorphic belts and plutonic-metamorphic complexes of southeastern Alaska

    SciTech Connect

    Brew, D.A.; Himmelberg, G.R.; Ford, A.B.; Loney, R.A. . Branch of Alaskan Geology Univ. of Missouri, Columbia, MO . Dept. of Geology)

    1993-04-01

    The Cordilleran orogen in southeastern Alaska includes 24 distinct magmatic belts, ranging in age from Cambrian to Holocene, that are defined by map relations, lithology, age, and chemical composition. The youngest magmatic features are Quaternary-age pre- and post-glacial volcanic rocks that occur in three major fields in the region, as well as in isolated locations. Cenozoic magmatic features consist of four major and three minor belts. The major Tkope-Portland Peninsula belt of Oligocene age includes both volcanic and plutonic rocks. The major calcalkalic Coast Mountains belt of early and middle Eocene age is the single largest magmatic feature of the region. Early Tertiary and latest Cretaceous magmatism is represented by the major calcalkalic great tonalite sill belt, a remarkable long and narrow feature along the west side of the Coast Mountains. Cretaceous and Jurassic intrusive rocks occur in five major belts and two minor belts in the region and Paleozoic intrusive rocks occur in four major and two minor belts. The three major plutonic-metamorphic complexes (PMC), from east to west, are: the Coast PMC in the Coast Mountains; the Glacier Bay-Chichag of plutonic complex (Chugach MC) in the northern outer islands. The Coast PMC records dynamothermal and regional contact metamorphic events related to regional plutonism within several juxtaposed terranes; its lengthy and complicated history is related to the Late Cretaceous collision of the Alexander and Wrangellia terranes and the Gravina overlap assemblage to the west against the Yukon prong and Stikine terrane to the east. The relatively simple Glacier Bay PC history is recorded as the roots of a Late Jurassic through late Early Cretaceous island arc that probably developed during the early stages of the above tectonic event. The complicated Chugach MC history developed during and after the Late Cretaceous collision of the Chugach terrane with the Wrangellia and Alexander terranes.

  11. Thondhjemite of the Talkeetna Mountains: An unusually large low-K pluton in Alaska's Peninsular terrane

    SciTech Connect

    Ford, A.B.; Arth, J.G.; Csejtey, B. )

    1993-04-01

    An unusually large, elongate Jurassic pluton of trondhjemite, about 120- by 10--15 km in dimensions, intruded Jurassic plutonic and metamorphic rocks of the Peninsular terrane in the central Talkeetna Mountains of south-central Alaska. Muscovite and biotite yield minimum ages of 150--145 Ma. The N40[degree]E-trending body is concordant with regional structures. It is the youngest member of a subduction-related Jurassic plutonic suite in the Peninsular terrane that, along with Wrangellia, was accreted to the North American continent in the middle Cretaceous. Rocks, commonly sheared, are medium to coarse grained and leucocratic (CI = 3--9). Biotite is the chief mafic mineral. Minor muscovite and garnet are common and green hornblende rare. Samples (n = 27) from the body's entire length have an average Mg[number sign] of 45 and an SiO[sub 2] continuum of 67--74% (avg. 70.7%). High Al[sub 2]O[sub 3] (14.4--17.9%, avg. 16.5%) is typical of continental trondhjemite. Averages for Zr (109 ppm) and Nb (3.5 ppm) and the ratios K/Rb (491) and Zr/Nb (34) are typical of orogenic igneous rocks of subduction origin. Four samples analyzed have low ([sup 87]Sr/[sup 86]Sr)[sub i] (avg. 0.7036). Very low Rb/Sr (avg. 0.027) is similar to Idaho batholith trondhjemites. REE patterns with low to moderate LREE and HREE with flat patterns and low contents suggest residual garnet or hornblende during partial melting or fractionation. The pluton appears homogeneous in outcrop. However, some geographic variations in chemistry, as in SiO[sub 2] contents and especially in Eu/Eu[sup *], suggest existence of perhaps three regionally separate plumbing systems, or chambers in which different processes such as plagioclase accumulation or hornblende fractionation were active.

  12. In Situ Assimilation Tracked By Trace Element Variation in Augite: Sausfjellet Pluton, North-Central Norway

    NASA Astrophysics Data System (ADS)

    Barnes, C. G.; Coint, N.; Yoshinobu, A. S.; Prestvik, T.; Barnes, M. A. W.

    2014-12-01

    The Sausfjellet pluton is a sub-circular, 445 Ma pluton in the Bindal Batholith. It was intruded into mid-crustal level (~700 MPa), high-grade rocks during Taconian assembly of the Helgeland Nappe Complex. Stage 1 of the pluton is massive pyroxene hornblende gabbro with poikilitic hornblende. Stage 2, the subject of this study, occupies the central and western parts of the pluton and is gradationally zoned from central, layered, xenolith-rich hornblende biotite two-pyroxene diorite + anorthosite, to western, massive, xenolith-poor hornblende biotite three-pyroxene quartz monzonite. Bulk-rock compositions are consistent with widespread accumulation of pyroxene + plagioclase. In order to separate effects of accumulation from assimilation, trace element zoning profiles in augite were used as a proxy for changes in melt composition. Augite is normally zoned, with incompatible elements increasing from cores to rims. However, trace element variation among samples plots as multiple trends that can be resolved into two broad groups that correspond to the central and western zones. Augite in the layered central zone has lower abundances of REE, Pb and Hf and higher abundances of Cr, V, Ni, Sr, and P compared to the western zone. The two trends intersect at low concentrations of incompatible elements such as Zr. Calculation of melts in equilibrium with augite, combined with AFC-type modeling, suggest that variation in augite Zr contents requires assimilation of Zr-rich rocks in all Stage 2 rocks. In the western zone, increases in Zr, Hf, REE and Pb suggest assimilation of Neoproterozoic gneisses that are host to the western zone; this conclusion is consistent with bulk-rock δ18O values. We conclude that assimilation of host rocks was widespread in this mid-crustal magma body, and that augite preserves a trace element record of differentiation (AFC) that is difficult to identify using bulk-rock compositions alone.

  13. Potassium-Argon and Lead-Alpha Ages of Plutonic Rocks, Bokan Mountain Area, Alaska.

    PubMed

    Lanphere, M A; Mackevett, E M; Stern, T W

    1964-08-14

    Most of the granitic rocks in the Bokan Mountain area, southeastern Alaska, are early Paleozoic (probably Ordovician) judged by potassium-argon and lead-alpha age measurements. The Bokan Mountain Granite, the youngest intrusive unit in the area, belongs to a Mesozoic plutonic episode. These age measurements are the first direct evidence for the emplacement of early Paleozoic granitic intrusive rocks close to the Pacific margin of North America. PMID:17754670

  14. Petrologic evidence for a plutonic igneous origin of anorthositic norite clasts in 67955 and 77017

    NASA Technical Reports Server (NTRS)

    Ashwal, L. D.

    1975-01-01

    Clasts of anorthositic norite in 67955 and 77017, and several other samples, are suggested to represent material which crystallized from a silicate magma in a plutonic environment. Although no statement can be made regarding the ultimate origin of the parent melt, its composition was relatively felsic, starting within the primary field of crystallization of either plagioclase or spinel. The sequence of crystallization was: plagioclase (and/or spinel) olivine - low-Ca pyroxene - high-Ca pyroxene.

  15. Petrogenesis and geodynamic implications of the Xiema and Ziyunshan plutons in Hunan Province, South China

    NASA Astrophysics Data System (ADS)

    Wang, Kai-Xing; Chen, Wei-Feng; Chen, Pei-Rong; Ling, Hong-Fei; Huang, Hui

    2015-11-01

    To understand the Mesozoic tectonic settings of the South China Block, samples collected from the Xiema and Ziyunshan plutons were analyzed with respect to zircon age, whole-rock and biotite chemical composition, whole-rock Sr-Nd and zircon Hf isotopic composition. Petrographic analysis and zircon LA-ICP-MS dating reveal that the Xiema pluton and the outer portion of the Ziyunshan pluton are composed of Late Triassic (Indosinian) biotite granodiorites and quartz monzonites with contemporaneous mafic microgranular enclaves (hereafter MMEs), whereas the inner part of the Ziyunshan pluton consists of Early Jurassic (Yanshanian) biotite granites and two-mica granites. Elemental and isotopic geochemical characteristics demonstrate that the Late Triassic granites are I-type granites and the Early Jurassic granites are S-type granites; furthermore, the data suggest that the two types of granites originated from different sources. The Late Triassic granites were mainly derived from the partial melting of Proterozoic meta-greywacke and meta-basalts at temperatures of 758-814 °C and log(fO2) values of -13 to -12. The residual mineral phases contain plagioclase, clinopyroxene/orthopyroxene, and quartz. At melting temperatures of 738-772 °C and log(fO2) values ranging from -15 to -13, the Early Jurassic granites originated from the partial melting of Proterozoic greywacke, with K-feldspar, ilmenite, clinopyroxene/orthopyroxene, and zircon serving as residues in the source. Geochronology and geochemistry data suggest that the Late Triassic granites were formed under the extension environment caused by the Early Mesozoic post multi-plate convergence tectonic setting, whereas the Early Jurassic granites formed in an intracontinental extensional setting.

  16. Tectonic significance of granitoid plutons from the Andasibe paragneiss belt, east-central Madagascar

    NASA Astrophysics Data System (ADS)

    Raharimahefa, T.

    2013-12-01

    The understanding of the crustal evolution of the central Madagascar is of major significance in the study of the Precambrian basement of Madagascar and the greater Gondwana supercontinent. The study area, known as Andasibe paragneiss defines a fold belt that stretches from Ambatondrazaka to Soavina area in eastern Madagascar and is intruded by extensive granitoid intrusions. The western part of Andasibe paragneiss lies within the crustal scale Angavo shear zone, and is characterized by fine to medium-grained foliated paragneiss, which also include biotite-hornblende gneiss, migmatitic quartzofeldspathic gneiss, sillimanite-bearing gneiss, garnet-bearing gneiss, graphitic gneiss intercalates with schist, quartzite, muscovite-bearing gneiss and marble. Three samples of granitoid plutons intruding the Andasibe paragneiss yielded isotope dilution-thermal ionization mass spectrometry (ID-TIMS) U-Pb zircon ages of 801.2×3.8Ma, 776.5×4.4Ma and 772.1×4.2Ma. These dates are interpreted to represent the crystallization ages of these rocks and are comparable to other reported U-Pb emplacement ages for granitoid plutons within and along the north-central margin of the Angavo shear zone, which are suggested to be related to ca. 820 Ma successor-arc plutonism. These granitoids pre-dates the Angavo shear zone and folds affecting the plutons foliation are believed to have formed during the East-African Orogen, which in this part of the Malagasy Precambrian basement, is considered to have associated with Neoproterozoic extensive magmatism ca. 820 Ma to 540 Ma.

  17. Geochemical evaluation of felsic plutonic rocks in the eastern and southeastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Du Bray, E.A.; Elliott, James E.; Stoeser, D.B.

    1983-01-01

    In a geochemical evaluation of the eastern and southeastern Arabian Shield, which included collection of 696 rock samples and 694 pan concentrate samples, a province of tin-anomalous granitoid plutons was defined. Pan concentrates collected in and around these plutons were enriched in tin and tungsten relative to the concentrate population. Rock samples of these leucocratic, muscovite-bearing, peraluminous granites contained anomalously high concentrations of lithium, fluorine, beryllium, lead, rubidium, niobium, yttrium, tin, bismuth, silver, and tungsten. Ten tin-anomalous plutons were located in the study area. The plutons are typically small, less than 10 km2 in areal extent, and circular to elliptical in plan view. The resource potential of these latest Proterozoic plutons has not been established; economically exploitable concentrations of tin, tungsten, molybdenum, or zinc may be present, and followup studies are warranted. Further, two of the plutons are characterized by higher than normal total-count radioactivity and have potential for uranium, thorium, or rare-earth element deposits.

  18. Multiple mafic and felsic magma interaction as exhibited in the Dartmouth Pluton, Avalon zone, southeastern Massachusetts

    SciTech Connect

    Hamidzada, N.A.; Hermes, O.D.; Murray, D.P. . Dept. of Geology)

    1993-03-01

    Dioritic to quartz monzonitic rocks of the Dartmouth Pluton exhibit excellently preserved, diverse features produced by mingling and mixing of mafic and felsic magma during multiple events. The related mafic and hybridized intermediate composition rocks occur both as discrete outcrop-sized masses or as enclaves within quartz monzonite or early-stage mixed rocks. Enclaves are rounded, lack chilled margins, and in some cases exhibit cuspate margins; they range in size from 1m--<1cm. Outcrops dominated by dioritic rock consist of well developed mafic pillows with inter-pillow infillings of hybridized rock that had been subjected to magma mixing during or prior to the final mingling process. Dioritic rocks are fine-grained with sparse plagioclase phenocrysts; they contain small, darker-colored enclaves indicative of preceding magma interaction. Major and trace element variation diagrams for this suite of rocks exhibit general linear trends consistent with mixing processes. Overall, field, petrographic, and geochemical relationships in the Dartmouth Pluton demonstrate: (1) widespread mingling of mafic and felsic magma, (2) variable degrees of mafic and felsic magma mixing, and (3) multiple and repeated episodes of mafic and felsic magma interaction. Significantly, some spatially associated dioritic and granitic rocks, including a 595 Ma alkali feldspar granite formerly considered to be part of the Dartmount Pluton, are geochemically related. Field mapping demonstrates that rocks of the mixed suite are intrusive into these rocks, thus establishing a maximum age, but raising the questions that the suite may be considerably younger.

  19. Formation of composite dykes by contact remelting and magma mingling: The Shaluta pluton, Transbaikalia (Russia)

    NASA Astrophysics Data System (ADS)

    Litvinovsky, B. A.; Zanvilevich, A. N.; Katzir, Y.

    2012-10-01

    A unique opportunity to study the source areas, from which composite dykes were injected, occurs in the Shaluta pluton, Transbaikalia, Russia. The major quartz syenite pluton was intruded by several synplutonic gabbro bodies of various sizes. Investigations of the contact zones between gabbro and host syenite showed that liquid basalt magma intruded the incompletely crystallized coarse-grained quartz syenite with T = 700-720 °C and caused contact remelting of the silicic rock at about 900-950 °C. Mechanical interaction between newly formed silicic melt and partially crystallized mafic magma resulted in extensive magma mingling. Chemical interaction was exhibited by migration of MgO, CaO, FeO∗, Sr, H2O and Cl from the basalt magma, whereas silica, alkalis, Rb and Ba migrated from the silicic refusion zone into the crystallized gabbro. Presence of melt inclusions with homogenization temperature ranging from 640 to 790 °C in quartz and attaining 850-900 °C in late clinopyroxene indicates that at least part of newly formed minerals crystallized from the hybrid melt. Mingled magmatic material was squeezed out inwards, into the host solid quartz syenite pluton and formed dyke-like apophyses that can be traced for a distance of 60-70 m from the contact zone. Apophyses have the same dimensions, structure and composition as typical composite dykes that are common in the roof pendant over the gabbro bodies and nearby the gabbro exposures.

  20. Age paradoxes of Devonian magmatism of the northeastern part of the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Terekhov, E. N.; Baluev, A. S.; Shcherbakova, T. F.; Ipat'eva, I. S.

    2012-02-01

    A structural-geochemical study has been conducted on the dikes of presumably Devonian mafic rocks confined to a small graben filled in with Riphean sedimentary rocks hosted by Early Precambrian granite-gneiss of the Murmansk block. It has been demonstrated that the dolerite dikes of this region can be considered as manifestations of trap magmatism whose products fill in the foundation of the East Barents riftogenic downfold. In turn, manifestations of alkaline and kimberlite rocks of the White Sea region are confined to the peripheral portion of the trap magnetism area. Zircons from dolerite transecting Late Riphean sediments examined in two laboratories have a concordant age of 2.74-2.72 Ba, while zircons from a similar dike located in granite-gneiss of the basement are characterized by an age range of 2700-155 Ma, and the concordant age based on 4 points is 790 Ma. All these factors indicate that the age determinations of the mafic rocks are ambiguous, particularly in the zone of transition from the center of the trap province to its periphery, where alkaline magmatism is observed.

  1. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassov's research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herring's group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  2. An unusually rich scuttle fly fauna (Diptera, Phoridae) from north of the Arctic Circle in the Kola Peninsula, N. W. Russia.

    PubMed

    Disney, R H L

    2013-01-01

    64 species of Phoridae, in 6 genera, are reported from the Kola Peninsula, north of the Arctic Circle. The new species Megaselia elenae and Megaselia kozlovi are described. 33 species of Megaselia, only known from females, are given code numbers. Keys to the species of all the females of Megaselia and Phora are provided; and also a key to the males European Megaselia species with a notopleural cleft. PMID:24194655

  3. An unusually rich scuttle fly fauna (Diptera, Phoridae) from north of the Arctic Circle in the Kola Peninsula, N. W. Russia

    PubMed Central

    Disney, R. H. L.

    2013-01-01

    Abstract 64 species of Phoridae, in 6 genera, are reported from the Kola Peninsula, north of the Arctic Circle. The new species Megaselia elenae and Megaselia kozlovi are described. 33 species of Megaselia, only known from females, are given code numbers. Keys to the species of all the females of Megaselia and Phora are provided; and also a key to the males European Megaselia species with a notopleural cleft. PMID:24194655

  4. From Migmatites to Plutons: Power Law Relationships in the Evolution of Magmatic Bodies

    NASA Astrophysics Data System (ADS)

    Soesoo, Alvar; Bons, Paul D.

    2015-07-01

    Magma is generated by partial melting from micrometre-scale droplets at the source and may accumulate to form >100 km-scale plutons. Magma accumulation thus spans well over ten orders of magnitude in scale. Here we provide measurements of migmatitic leucosomes and granitic veins in drill cores from the Estonian Proterozoic basement and outcrops at Masku in SW Finland and Montemor-o-Novo, central Portugal. Despite the differences in size and number of measured leucosomes and magmatic veins, differences in host rock types and metamorphic grades, the cumulative width distribution of the studied magmatic leucosomes/veins follows a power law with exponents usually between 0.7 and 1.8. Published maps of the SE Australian Lachlan Fold Belt were used to investigate the distribution of granitoid pluton sizes. The granites occupy ca. 22 % of the 2.6 × 105 km2 area. The cumulative pluton area distributions show good power law distributions with exponents between 0.6 and 0.8 depending on pluton area group. Using the self-affine nature of pluton shapes, it is possible to estimate the total volume of magma that was expelled from the source in the 2.6 × 105 km2 map area, giving an estimated 0.8 km3 of magma per km2. It has been suggested in the literature that magma batches in the source merge to form ever-bigger batches in a self-organized way. This leads to a power law for the cumulative distribution of magma volumes, with an exponent m V between 1 for inefficient melt extraction, and 2/3 for maximum accumulation efficiency as most of the volume resides in the largest batches that can escape from the source. If m V ≥ 1, the mass of the magma is dominated by small batches; in case m = 2/3, about 50 % of all magma in the system is placed in a single largest batch. Our observations support the model that the crust develops a self-organized critical state during magma generation. In this state, magma batches accumulate in a non-continuous, step-wise manner to form ever

  5. The Holocene vegetation history of the Khibiny Mountains: implications for the post-glacial expansion of spruce and alder on the Kola Peninsula, northwestern Russia

    NASA Astrophysics Data System (ADS)

    Kremenetski, Constantin; Vaschalova, Tatiana; Sulerzhitsky, Leopold

    1999-02-01

    Pollen and peat botanical investigations of the Lutnermayok peat bog, Kola Peninsula, northwestern Russia, were carried out, and 21 surface pollen samples were studied. Combined with previous studies our data form the basis for the vegetation history over the last 7000 yr of the Khibiny Mountains. Pinus sylvestris was the dominant species between 7000 and 5000 yr BP and Picea obovata penetrated to the Khibiny Mountains ca. 5500/5300 yr BP. Since 4500 yr BP, Picea replaced Pinus in major parts of the area and dominated the forest cover. Picea immigrated to the Kola Peninsula after 7000 yr BP. There were two paths of spruce migration: from the southeast and the southwest. Grey alder, Alnusincana, immigrated to the Kola Peninsula from the southwest and northwest about ca. 8000 yr BP. Grey alder has been restricted to its modern range since 4000 yr BP. The range of vertical movement of the treeline in Khibiny Mountains during the last 700 yr was 240-260 m, which corresponds to an amplitude of summer temperature change of 2°C.

  6. Fingerprinting and validation of a LC-DAD method for the analysis of biflavanones in Garcinia kola-based antimalarial improved traditional medicines.

    PubMed

    Tshibangu, P Tshisekedi; Kapepula, P Mutwale; Kapinga, M J Kabongo; Lupona, H Kabika; Ngombe, N Kabamba; Kalenda, Dibungi T; Jansen, O; Wauters, J N; Tits, M; Angenot, L; Rozet, E; Hubert, Ph; Marini, R D; Frédérich, M

    2016-09-01

    African populations use traditional medicines in their initial attempt to treat a range of diseases. Nevertheless, accurate knowledge of the composition of these drugs remains a challenge in terms of ensuring the health of population and in order to advance towards improved traditional medicines (ITMs). In this paper chromatographic methods were developed for qualitative and quantitative analyses of a per os antimalarial ITM containing Garcinia kola. The identified analytical markers were used to establish TLC and HPLC fingerprints. G. kola seeds were analysed by HPLC to confirm the identity of the extract used by the Congolese manufacturer in the ITM. The main compounds (GB1, GB2, GB-1a and Kolaflavanone) were isolated by preparative TLC and identified by UPLC-MS and NMR. For the quantification of the major compound GB1, a simple and rapid experimental design was applied to develop an LC method, and then its validation was demonstrated using the total error strategy with the accuracy profile as a decision tool. The accurate results were observed within 0.14-0.45mg/mL range of GB1 expressed as naringenin. The extracts used in several batches of the analysed oral solutions contained GB1 (expressed as naringenin) within 2.04-2.43%. Both the fingerprints and the validated LC-DAD were found suitable for the quality control of G. kola-based raw material and finished products, respectively. PMID:27343901

  7. INSTALLATION OF A POST-ACCIDENT CONFINEMENT HIGH-LEVEL RADIATION MONITORING SYSTEM IN THE KOLA NUCLEAR POWER STATION (UNIT 2) IN RUSSIA

    SciTech Connect

    GREENE,G.A.; GUPPY,J.G.

    1998-09-01

    This is the final report on the INSP project entitled, ``Post-Accident Confinement High-Level Radiation Monitoring System'' conducted by BNL under the authorization of Project Work Plan WBS 1.2.2.6 (Attachment 1). This project was initiated in February 1993 to assist the Russians in reducing risks associated with the continued operation of older Soviet-designed nuclear power plants, specifically the Kola VVER-440/230 Unit 2, through improved accident detection capability, specifically by the installation of a dual train high-level radiation detection system in the confinement of Unit 2 of the Kola NPP. The major technical objective of this project was to provide, install and make operational the necessary hardware inside the confinement of the Kola NPP Unit 2 to provide early and reliable warning of the release of radionuclides from the reactor into the confinement air space as an indication of the occurrence of a severe accident at the plant. In addition, it was intended to provide hands-on experience and training to the Russian plant workers in the installation, operation, calibration and maintenance of the equipment in order that they may use the equipment without continued US assistance as an effective measure to improve reactor safety at the plant.

  8. The results of marine electromagnetic sounding with a high-power remote source in the Kola Bay in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Grigoriev, V. F.; Korotaev, S. M.; Kruglyakov, M. S.; Orekhova, D. A.; Popova, I. V.; Tereshchenko, E. D.; Tereshchenko, P. E.; Schors, Yu. G.

    2013-05-01

    The first Russian six-component seafloor electromagnetic (EM) receivers were tested in an experiment carried out in Kola Bay in the Barents Sea. The signals transmitted by a remote high-power ELF source at several frequencies in the decahertz range were recorded by six receivers deployed on the seafloor along the profile crossing the Kola Bay. Although not all the stations successfully recorded all the six components due to technical failures, the quality of the data overall is quite suitable for interpretation. The interpretation was carried out by the three-dimensional (3D) modeling of an electromagnetic field with neural network inversion. The a priori geoelectrical model of Kola Bay, which was reconstructed by generalizing the previous geological and geophysical data, including the data of the ground magnetotelluric sounding and magnetovariational profiling, provided the EM fields that are far from those measured in the experiment. However, by a step-by-step modification of the initial model, we achieved quite a satisfactory fit. The resulting model provides the basis for introducing the corrections into the previous notions concerning the regional geological and geophysical structure of the region and particularly the features associated with fault tectonics.

  9. K-alkaline rocks and lamproites of Tomtor massif

    NASA Astrophysics Data System (ADS)

    Vladykin, Nikolai

    2015-04-01

    Tomtor massif of the largest volcano-plutonic deep alkaline-carbonatite massifs world central type. Area of massif occupy 240 km2 and carbonatites stock is 40 km2. The super large deposit of Nb, TR, Y, Sc, Sr ,REE (Frolov et al. 2001)is found within the massif. The numerical publication are devoted to the ore mineralization there. But the geological struc-ture of the massif and the chemistry of its constituting rocks are not well understood. We obtained new ages based on U-Pb zircon and mica Ar-Ar method (Kotov, Vladykin et al. 2014 Vladykin et al. 2015). The massif was created in 2 stages: 700 and 400 Ma. We (Vla-dykin et al 1998) found rocks of lamproite series and proposed a new scheme of magmatism and the ore.genesis (Vladykin 2007, 2009). Biotite - pyroxenite, peridotite originated in first stage and then intruded iolites, nepheline and alkali syenite. Syenites occupy 70% of -massif and contain 12-13% K2O and 2-4% Na2O showing the K-alkaline-ultramafic nature of Tomtor volcano-plutonic massif (Vladykin 2009). The first stage was accomplished by nelsonitov calcite, dolomite and ankerite carbonatites. Second stage (400Ma) volcanics picrite - lamproite veins and eruptive breccias meli-lite, melanephelinites, tinguaites appered. These rocks are cut by carbonatites of second stage. It was finished by intensive explosive eruption of a silicate (lamproite) tuffs lavobrec-cia kimberlite formed Ebelyakhdiamondiferous placer, melilite rocks in diatremes (feeders), as well as carbonate-phosphate (kamaforite) explosive tuffs with siderite ores. This carbona-tite complex is preserved within the subsidence caldera. Tuff eruption in conjunction with gas and hydrothermal activity determined its rare metal mineralization. These rocks contain to: Nb- 21%, TR-15%, Y-1.5%, Sc-1%, Zr- 0,5% Zn-, Sr-6%, Ti-8%, Ba-4%, V - 8000 ppm, Be- 300 ppm, Ga- 80 ppm, Cr- 1200ppm, Ni- 230 ppm, Mo- 145 ppm, Pb- 4300 ppm, Th- 1500 ppm, U-193 ppm. Picrite - olivine (rare leucite) lamproite and

  10. Development of modal layering in granites: a case study from the Carna Pluton, Connemara, Ireland

    NASA Astrophysics Data System (ADS)

    McKenzie, Kirsty; McCarthy, William; Hunt, Emma

    2016-04-01

    Modal layering in igneous rocks uniquely record dynamic processes operating in magma chambers and also host a large proportion of Earth's strategic mineral deposits. This research investigates the origin of biotite modal layering and primary pseudo-sedimentary structures in felsic magmas, by using a combination of Crystal Size Distribution (CSD) analysis and Electron Probe Microanalysis (EPMA) to determine the mechanisms responsible for the development of these structures in the Carna Pluton, Connemara, Ireland. The Carna Pluton is a composite granodiorite intrusion and is one of five plutons comprising the Galway Granite Complex (425 - 380 Ma). Prominent 30 cm thick modal layers are defined by sharp basal contacts to a biotite-rich (20%) granite, which grades upward over 10 cm into biotite-poor, alkali-feldspar megacrystic granite. The layering strikes parallel to, and dips 30-60° N toward the external pluton contact. Pseudo-sedimentary structures (cross-bedding, flame structures, slumping and crystal graded bedding) are observed within these layers. Petrographic observations indicate the layers contain euhedral biotite and fresh undeformed quartz and feldspar. Throughout the pluton, alkali-feldspar phenocrysts define a foliation that is sub-parallel to the strike of biotite modal layers. Together these observations indicate that the intrusion's concentric foliation, biotite layers and associated structures formed in the magmatic state and due to a complex interaction between magma flow and crystallisation processes. Biotite CSDs (>250 crystals per sample) were determined for nine samples across three biotite-rich layers in a single unit. Preliminary CSD results suggest biotite within basal contacts accumulated via fractional crystallisation within an upward-growing crystal pile, likely reflecting the yield strength of the magma as a limiting factor to gravitational settling of biotite. This is supported by the abrupt decrease in mean biotite crystal size across

  11. Thermochronology and Cooling Histories of Intrusive Suites: Implications for Incremental Pluton Assembly

    NASA Astrophysics Data System (ADS)

    Davis, J.; Coleman, D.; Heizler, M.

    2007-12-01

    Debate persists about the timescales and mechanisms of pluton emplacement and batholith formation. An understanding of whether plutons accumulate as large masses of magma or as an incremental series of pulses, in which the active magma body is small relative to the final pluton, is important for understanding the relationship between volcanoes and plutons. If volcanic eruptions < 1000 km3 are the most common size and large ignimbrites are rare, it follows that most plutons should record accumulations of small volumes of melt that were emplaced over long time intervals (millions to tens of millions of years) and therefore preserve predictable, protracted thermal histories. Modeling predicts observable differences in thermal histories of plutons and their aureoles that can be tested through thermochronology. Application of multiple chronometers (zircon and titanite U-Pb TIMS; hornblende, biotite, and K-feldspar 40Ar/39Ar; zircon and titanite (U-Th)/He) combined with K-feldspar multiple diffusion domain (MDD) modeling were used to determine the thermal history and to calibrate thermal models of two eastern California, Sierra Nevada batholith intrusive suites; the dike-like John Muir Intrusive Suite (JMIS) and the laccolithic Mt. Whitney Intrusive Suite (MWIS), and their wall rocks. Preliminary results of (U-Th)/He zircon data from the JMIS and its wall rock (the Tinemaha granodiorite) show a tight cluster of dates ranging from 75.6 to 70.4 Ma. The JMIS is thought to be mesozonal (8 to 11 km) and these data are interpreted as resulting from exhumation and additional 40Ar/39Ar data are required to determine if the thermal history reflects incremental intrusions. In contrast to the JMIS, preliminary (U-Th)/He zircon data from the MWIS and its wall rock (the Bullfrog pluton) show a wide range in dates ranging from 91.4 to 74.6 Ma that are interpreted to reflect reheating events. Amphibole 40Ar/39Ar inverse isochron dates, K- feldspar age spectra, and (U-Th)/He zircon data

  12. Fabric and microstructural analysis of the Loch Borralan pluton, Northwest Highlands, Scotland

    NASA Astrophysics Data System (ADS)

    Calhoun, Justin

    The Loch Borralan pluton was emplaced within the Assynt Region of the Moine Thrust zone during the Scandian event (ca. 435-425 Ma) of the Caledonian Orogeny (478-425 Ma). It consists of two major magma suites, the syenitic early suite (431.1 +/- 1.2 Ma), and the quartz syenitic later suite (429.2 +/- 0.5 Ma). The region is characterized by a series of in-sequence thrust faults that strike NE-SW and dip approximately 20° to the SE, including (from lower to upper): the Sole Thrust, the Borralan Thrust (hypothesized, but not exposed), the Ben More Thrust, and the Moine Thrust. A series of imbricate thrusts between the Sole and Borralan Thrusts juxtapose repeated Cambrian and Ordovician strata. The Loch Borralan pluton intruded between the Sole and Ben More thrust faults, and may be bounded below by a hypothesized Borralan Thrust fault. Based on the overlap in pluton crystallization age and orogenic activity, the combination of macroscopic field lineation and foliation measurements, anisotropy of magnetic susceptibility (AMS) lineation and foliations measurements, mineral shape preferred orientation (SPO) analysis, and petrographic deformation microstructure analysis will be used to determine if the pluton expresses deformation features and fabrics corresponding to thrust fault tectonics. The dominant magnetic mineralogy as determined by thermomagnetic data and hysteresis plots was determined to be magnetite and titanomagnetite. Some paramagnetic components were seen in the early suite, and can be attributed to biotite. Both minerals contributed to the AMS signal that was used to interpret pluton fabrics. The pluton contains S>L (foliation stronger than lineation) fabrics throughout, defined by alignment of alkali feldspar grains. The foliation strike of both the early and late suites are subparallel to the thrust faults, providing evidence that the fabrics are related to deformation. The early suite is only well exposed in the southeast at the top of the Borralan

  13. Intrusive rocks of the Holden and Lucerne quadrangles, Washington; the relation of depth zones, composition, textures, and emplacement of plutons

    USGS Publications Warehouse

    Cater, Fred W.

    1982-01-01

    The core of the northern Cascade Range in Washington consists of Precambrian and upper Paleozoic metamorphic rocks cut by numerous plutons, ranging in age from early Triassic to Miocene. The older plutons have been eroded to catazonal depths, whereas subvolcanic rocks are exposed in the youngest plutons. The Holden and Lucerne quadrangles span a -sizeable and representative part of this core. The oldest of the formations mapped in these quadrangles is the Swakane Biotite Gneiss, which was shown on the quadrangle maps as Cretaceous and older in age. The Swakane has yielded a middle Paleozoic metamorphic age, and also contains evidence of zircon inherited from some parent material more than 1,650 m.y. old. In this report, the Swakane is assigned an early Paleozoic or older age. It consists mostly of biotite gneiss, but interlayered with it are scattered layers and lenses of hornblende schist and gneiss, clinozoisite-epidote gneiss, and quartzite. Thickness of the Swakane is many thousands of meters, and the base is not exposed. The biotite gneiss is probably derived from a pile of siliceous volcanic rocks containing scattered sedimentary beds and basalt flows. Overlying the Swakane is a thick sequence of eugeosynclinal upper Paleozoic rocks metamorphosed to amphibolite grade. The sequence includes quartzite and thin layers of marble, hornblende schist and gneiss, graphitic schist, and smaller amounts of schist and gneiss of widely varying compositions. The layers have been tightly and complexly folded, and, in places, probably had been thrust over the overlying Swakane prior to metamorphism. Youngest of the supracrustal rocks in the area are shale, arkosic sandstone, and conglomerate of the Paleocene Swauk Formation. These rocks are preserved in the Chiwaukum graben, a major structural element of the region. Of uncertain age, but possibly as old as any of the intrusive rocks in the area, are small masses of ultramafic rocks, now almost completely altered to

  14. Multiple intrusive events in the formation of granite plutons: Evidence from the Lee Vining Diorite, eastern California

    SciTech Connect

    McCarthy, T.C.; Furman, T. . Dept. of Environmental Sciences); Reid, J.B. Jr. . School of Natural Sciences)

    1993-03-01

    The Cretaceous Lee Vining Diorite (eastern Sierra Nevada) preserves important field, petrographic and geochemical evidence for complex intrusive events in a mesozonal magma body. The pluton comprises primarily light grey unfoliated quartz diorite, with color index varying between 10--50. A 1,400 m transect across the pluton yielded samples of (1) mafic diorite from a 300 m thick sill, (2) disaggregated basaltic dikes, (3) rounded mafic inclusions and (4) rounded hornblende-cumulate inclusions in addition to (5) quartz diorite of variable texture and color index. Internal intrusive contacts are observed in several places; the upper contact of the sill is indistinct locally, suggesting a low thermal contrast with host quartz diorite at the time of intrusion. Textural analysis of plagioclase crystals form throughout the pluton indicates a history of pervasive magma mixing. In each thin section, 20--90% of the plagioclase crystals are pitted or corroded, and up to 50% of these crystals are also completely zoned. Disequilibrium plagioclase crystals are not preferentially associated with mafic inclusion, but are distributed randomly within the pluton. Major and trace element analyses of over 40 samples taken along the transect show variations that cannot be explained through simple magma mixing or through progressive crystallization of a single magma body. The pluton is not zoned geochemically, but rather comprises small regions (< 200 m across) of uniform composition that are juxtaposed randomly. Chemical variations across the pluton likely result from both missing of small magma batches and fractional crystallization of mixed magmas. This interpretation is consistent with field and textural requirements for multiple intrusive episodes in the formation of the diorite pluton.

  15. Consistent magmatic and magnetic anisotropy data in La Gloria Pluton, central Chile: Implications for the magma flow record in a shallow pluton

    NASA Astrophysics Data System (ADS)

    Payacan, I.; Gutierrez, F. J.; Bachmann, O.; Parada, M.

    2012-12-01

    The magmatic origin of the anisotropy of magnetic susceptibility (AMS) is examined in comparison with magmatic anisotropy data in a small, shallow, silicic magma reservoir in the upper crust. La Gloria Pluton (LGP) is a 10 Ma granodiorite/quartz monzonite of about 250 km3 located in the southern Andes, central Chile. LGP represents a particularly simple case of a silicic intrusion which was assembled in a few pulses and cooled over a short time interval. Hornblende, biotite and minor magnetite are ubiquitous mafic phases. The AMS tensor indicates that magnetic fabric has an oblate shape (i.e. magnetic foliation is higher than magnetic lineation). Lineations are weak (values up to 1.05), have a N-NW trend with a nearly horizontal dip and represent axisymmetric convection parallel to the main pluton elongation. Foliations are more pronounced (values up to 1.14), having NW trends and dips that vary gradually from vertical at the walls, to horizontal at the center and near the roof of the chamber. We interpret this to represent shear localization near the magma locking point along solidification fronts. Magmatic anisotropy data were obtained by measuring mineral length, width and orientation in the three main planes of the AMS tensor. We define the planes Pmax, Pint, and Pmin as orthogonal to the maximum, intermediate, and minimum axes of the AMS tensor, respectively. Mineral data were collected for plagioclase and amphibole + bitotite independently. For each site, the Bingham distribution with 95% of confidence is used to determine the mean mineral orientation and their angle difference with the AMS axes. Preliminary results indicate that mean crystal orientations are well defined for Pmax and Pint for all analyzed minerals, but Pmin is only well constrained for amphibole + bitotite and poorly constrained for plagioclase. Angle differences generally decrease with magnetic anisotropy but are independent of the size and aspect ratio of the crystals. Mean values of

  16. The Middle Fork Plutonic Complex: A plutonic association of coeval peralkaline and metaluminous magmas in the north-central Alaska Range

    SciTech Connect

    Solie, D.N.

    1988-01-01

    The 57 m.y. Middle Fork Plutonic Complex (MFPC) intrudes Paleozoic metasedimentary rocks south of the Farewell Fault zone in the north-central Alaska Range. Though spatially related to the late Cretaceous - Early Tertiary subduction-related Alaska Range batholith, MFPC is more characteristic of an extensional or anorogenic setting. A swarm of basalt, hawaiite and rhyolite dikes east of the complex intruded, and was intruded by, the plutonic rocks. Approximately 30% of the exposed rock in the 125 km[sup 2] complex is hedenbergite - fayalite syenite, [approx equal]20% is peralkalin arfvedsonite-biotite alkali-feldspar granite (AF granite), and [le]20% is pyroxene-olivine-biotite gabbro. The rest is a mixed unit including clinopyroxene-biotite-amphibole diorite, and hornblende-biotite granite (HB granite). K-Ar and Rb-Sr radiometric dating of rock types shows that they are coeval. Their close spatial and temporal relationships led to complex magmatic interactions. Calculated initial [sup 87]Sr/[sup 86]Sr for gabbro and diorite group is around 0.705 to 0.706. HB granites are heterogeneous, but fall mostly around 0.707 to 0.708. Hypersolvus syenites and AF granites form an isochron with initial [sup 87]Sr/[sup 86]Sr of 0.70965. These groupings suggest that at least three different magmas formed the MFPC; scatter of isotopic data reflects mutual contamination and assimilation. Consanguinous hypersolvus syenite and AF granite mineralogy appears to be controlled by fluorine in the magma chamber. Eruptive stratigraphy, as predicted by intrusive history of MFPC, compares favorably with volcanic stratigraphies of peralkaline volcanic systems worldwide, and MFPC may be modelled as the root zone of a peralkaline volcanic system.

  17. Zircon U-Pb ages and tectonic implications of Paleozoic plutons in northern West Junggar, North Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Chen, Jia-Fu; Han, Bao-Fu; Ji, Jian-Qing; Zhang, Lei; Xu, Zhao; He, Guo-Qi; Wang, Tao

    2010-03-01

    North Xinjiang, Northwest China, is made up of several Paleozoic orogens. From north to south these are the Chinese Altai, Junggar, and Tian Shan. It is characterized by widespread development of Late Carboniferous-Permian granitoids, which are commonly accepted as the products of post-collisional magmatism. Except for the Chinese Altai, East Junggar, and Tian Shan, little is known about the Devonian and older granitoids in the West Junggar, leading to an incomplete understanding of its Paleozoic tectonic history. New SHRIMP and LA-ICP-MS zircon U-Pb ages were determined for seventeen plutons in northern West Junggar and these ages confirm the presence of Late Silurian-Early Devonian plutons in the West Junggar. New age data, combined with those available from the literature, help us distinguish three groups of plutons in northern West Junggar. The first is represented by Late Silurian-Early Devonian (ca. 422 to 405 Ma) plutons in the EW-striking Xiemisitai and Saier Mountains, including A-type granite with aegirine-augite and arfvedsonite, and associated diorite, K-feldspar granite, and subvolcanic rocks. The second is composed of the Early Carboniferous (ca. 346 to 321 Ma) granodiorite, diorite, and monzonitic and K-feldspar granites, which mainly occur in the EW-extending Tarbgatay and Saur (also spelled as Sawuer in Chinese) Mountains. The third is mainly characterized by the latest Late Carboniferous-Middle Permian (ca. 304 to 263 Ma) granitoids in the Wuerkashier, Tarbgatay, and Saur Mountains. As a whole, the three epochs of plutons in northern West Junggar have different implications for tectonic evolution. The volcano-sedimentary strata in the Xiemisitai and Saier Mountains may not be Middle and Late Devonian as suggested previously because they are crosscut by the Late Silurian-Early Devonian plutons. Therefore, they are probably the eastern extension of the Early Paleozoic Boshchekul-Chingiz volcanic arc of East Kazakhstan in China. It is uncertain at

  18. Long-term aerosol and trace gas measurements in Eastern Lapland, Finland: the impact of Kola air pollution to new particle formation and potential CCN

    NASA Astrophysics Data System (ADS)

    Kyrö, Ella-Maria; Väänänen, Riikka; Kerminen, Veli-Matti; Virkkula, Aki; Asmi, Ari; Nieminen, Tuomo; Dal Maso, Miikka; Petäjä, Tuukka; Keronen, Petri; Aalto, Pasi; Riipinen, Ilona; Lehtipalo, Katrianne; Hari, Pertti; Kulmala, Markku

    2014-05-01

    Sulphur and primary emissions have been decreasing largely all over Europe, resulting in improved air quality and decreased direct radiation forcing by aerosols. The smelter industry in Kola Peninsula is one of largest sources of anthropogenic SO2 within the Arctic domain and since late 1990s the sulphur emissions have been decreasing rapidly (Paatero et al., 2008; Prank et al., 2010). New particle formation (NPF) is tightly linked with the oxidizing product of SO2, namely sulphuric acid (H2SO4), since it is known to be the key component in atmospheric nucleation (Sipilä et al., 2010). Thus, decreasing sulphur pollution may lead to less NPF. However, low values of condensation sink (CS), which is determined by the amount of pre-existing particles, favours NPF. We used 14 years (1998-2011) of aerosol number size distribution and trace gas data from SMEAR I station in Eastern Lapland, Finland, to investigate these relationships between SO2, NPF and CS. The station is a clean background station with occasional sulphur pollution episodes when the air masses arrive over Kola Peninsula. We found that while SO2 decreased by 11.3 % / year, the number of clear NPF event days was also decreasing by 9.9 % / year. At the same time, CS was decreasing also (-8.0 % / year) leading to formation of more particles per single NPF event (J3 increased by 29.7 % / year in 2006-2011) but the low vapour concentrations of H2SO4 (proxy decreased by 6.2 % / year) did not allow them to grow into climatically relevant sizes. Over the time, concentrations of potential CCN (cloud condensing nuclei) were also decreasing with more moderate pace, -4.0 % / year. The events started on average earlier after sunrise when the SO2 concentration during the start of the event was higher and NPF occurred more frequently in air masses which were travelling over Kola. Despite the total decrease in sulphur pollution originating from Kola there is currently no evidence of cleaning of the emissions, rather the

  19. Anode conductor for alkaline cells

    SciTech Connect

    Schrenk, D.J.; Murphy, P.E.

    1988-12-13

    This patent describes an electrochemical cell comprised of an anode comprised of zinc; a cathode; and alkaline electrolyte; and a current collector comprised of a silicon bronze alloy that is comprised of 85-98% by weight copper and 1-5% by weight silicon with the remainder being comprised of at least one of manganese, iron, zinc, aluminum, tin, lead, or mixtures thereof; and a strip of metal tab stock welded to the current collector, the tab stock being a metal other than silicon bronze alloy.

  20. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more than two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  1. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  2. Petrogenesis and tectonic implications of the high-K Alamas calc-alkaline granitoids at the northwestern margin of the Tibetan Plateau: Geochemical and Sr-Nd-Hf-O isotope constraints

    NASA Astrophysics Data System (ADS)

    Zhang, Qichao; Liu, Yan; Huang, He; Wu, Zhenhan; Zhou, Qing

    2016-09-01

    The Alamas granitoid pluton in the eastern part of the Western Kunlun Orogen, the northwestern margin of the Tibetan Plateau, is composed of quartz diorite. Zircon separates from the pluton has SIMS U-Pb age of ∼446 Ma. Rocks from the pluton have a narrow range of SiO2 (56.84-62.57 wt%), MgO (1.76-2.94 wt%), and total alkalis (Na2O + K2O = 5.14-9.59 wt%), and are metaluminous and high-K calc-alkaline to shoshonitic in composition. They are enriched in light rare earth elements (LREEs), with (La/Yb)N = 14-25, and show weakly negative Eu anomalies. These rocks are relatively enriched in Sr (472-676 ppm) and Ba (435-2388 ppm), and depleted in Nb, Ta, Th, and Ti. Their εNd(t) values range from -6.4 to -8.4, and (87Sr/86Sr)i = 0.7184-0.7200. Zircons from the pluton show εHf(t) values of -1.4 to -8.8, and δ18O = 6.4-9.0‰. Geochemical data indicate that the granitoids were likely derived from the reworking of an ancient, deep crustal source, influenced by a minor mantle-derived component. Magmatic differentiation was dominated by the fractional crystallization of hornblende, biotite, and accessory minerals such as apatite, allanite, and Fe-Ti oxides. In summary, the Late Ordovician Alamas pluton is an I-type granitoid that was emplaced in a post-collisional environment, suggesting that this tectonic stage had already initiated prior to ∼445 Ma.

  3. Asymmetric textural and structural patterns of a granitic body emplaced at shallow levels: The La Chinchilla pluton, northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Macchioli Grande, M.; Alasino, P. H.; Rocher, S.; Larrovere, M. A.; Dahlquist, J. A.

    2015-12-01

    New mapping and a detailed structural study of the La Chinchilla stock, Sierra de Velasco, NW Argentina, suggest an asymmetrical shape of the pluton and provide strong evidence for its shallow emplacement depth. The pluton is a Lower Carboniferous monzogranite composed of K-feldspar, quartz, plagioclase and biotite. It exhibits an internal asymmetric textural zoning, defined by porphyritic granite in the southeastern region to equigranular granite in the northwestern region. The presence of subhorizontal dikes in the northwestern area, where the contacts dip shallowly, and subvertical dikes intruding the host rock nearby steep-dipping intrusive contacts in the southeastern region are compatible with an overall asymmetrical shape and internal structure of this pluton. Considering published crystallization ages, a dominant strain field occurring at around 12 Ma is inferred based on magmatic fabrics in the pluton and its host rock (the Huaco pluton), with a principal shortening direction oriented SW-NE, consistent with the general NW-SE strike of the body. Field evidence supports brittle fracturing and block displacement as the dominant emplacement mechanism, suggesting that magmatic stoping dominated during the late stage of the evolution of the magma chamber.

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

  5. Timing of Proterozoic deformation, plutonism, and metamorphism in the Los Pinos Mountains, Central New Mexico

    SciTech Connect

    Shastri, L.L. . Dept. of Geology); Bowring, S.A. )

    1992-01-01

    Geochronologic, structural, and metamorphic studies within the Los Pinos Mountains (LPM), central NM provide new insights into the Proterozoic geologic history of this area. The LPM consist of a NE-trending, NW-dipping sequence of complexly deformed amphibolites and felsic schists. These have been intruded by a pervasively deformed granitic pluton. Two predominant deformational fabrics exist in the LPM. S1 is an early northwest-trending foliation, commonly parallel to compositional layering, which is folded about S2. S2 is axial planar foliation to tight to isoclinal folds and is the regional NE-trending fabric. Other fabrics and complex fold interference patterns may be related to localized strain partitioning around granitic bodies. A network of granitic dikes associated with the pluton crosscuts S2 but contains a weak foliation parallel to S2, suggesting synkinematic intrusion of the dikes. Regional metamorphism in the LPM took place at upper greenschist to lower amphibolite facies. Electron microprobe traverses of garnets show compositional variation indicative of growth zoning. No abrupt changes in composition representative of multiple metamorphic events are observed. Garnet-biotite geothermometry yields average rim temperatures of 454 [+-] 50 C. U-Pb geochronology of zircons from amphibolite, granite, and a granite dike indicates essentially the same age for all three units (1.66 Ga). The amphibolite contains abundant zircons which have complex morphologies typical of metamorphic growth; however, an igneous origin cannot yet be precluded. Spheres from the same amphibolite yield a near concordant age of 1.62 Ga. Thus, deformation, plutonism, and possibly the peak of metamorphism, were coeval at ca. 1.66 Ga, with metamorphism cooling through the blocking temperature of sphene at 1.62 Ga. The LPM are similar to other mountain ranges in south-central New Mexico where 1.66 Ga ages have been reported.

  6. River Valley pluton, Ontario: A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

    SciTech Connect

    Ashwal, L.D. ); Wooden, J.L. )

    1989-03-01

    The River Valley pluton is a ca. 100 km{sup 2} body of anorthositic and gabbroic rocks located about 50 km northeast of Sudbury, Ontario. The pluton is situated entirely within the Grenville Province, but its western margin is a series of imbricate thrust faults associated with the Grenville Front Tectonic Zone. It is dominated by coarse leuconorite and leucogabbro, with lesser anorthosite, gabbro, and rare ultramafics. Igneous textured rocks are abundant and consist of plagioclase (An{sub 60-70}) charged with Fe-Ti oxide inclusions, low Ca pyroxene (orthopyroxene and/or inverted pigeonite) and augite. The most unfractionated rocks are minor olivine gabbros with Fo{sub 70-80}. A variety of deformed and recrystallized equivalents of the igneous-textured rocks is also present, and these are composed largely of calcic plagioclase and hornblende. An Sm-Nd isochron from 3 igneous-textured leucogabbros and an augite mineral separate gives 2,377 {plus minus} 68 Ma, implying slight disturbance of the Sm-Nd whole-rock-mineral system during later metamorphism. The Rb-Sr system has been substantially disturbed, giving an age of 2,185 {plus minus} 105 Ma, which is similar to internal Pb-Pb isochron ages of 2,165 {plus minus} 130 Ma and 2,100 {plus minus} 35 Ma for two igneous-textured rocks. Initial isotopic ratios for the River Valley pluton correspond to single-stage model parameters of {mu} = 8.06, {epsilon}{sub Nd} = O to {minus}3, and I{sub Sr} = 0.7015 to 0.7021. Collectively, these suggest either an enriched mantle source or crustal contamination of a mantle-derived magma. The crustal component involved must have been older and more radiogenic than the majority of rocks exposed at the surface in the nearby Superior Province.

  7. Ti in zircon from the Boggy Plain zoned pluton: implications for zircon petrology and Hadean tectonics

    NASA Astrophysics Data System (ADS)

    Ickert, R. B.; Williams, I. S.; Wyborn, D.

    2011-08-01

    The understanding of zircon crystallization, and of the Ti-in-zircon thermometer, has been enhanced by Ti concentration measurements of zircon from a small, concentrically zoned pluton in south-eastern Australia, the Boggy Plain zoned pluton (BPZP). Zircon crystals from rocks ranging in composition from gabbro to aplite were analysed for U-Th-Pb dating and Ti concentrations by an ion microprobe. Geochronological data yield a 206Pb/238U age of 417.2 ± 2.0 Ma (95% confidence) and demonstrate the presence of older inherited or xenocrystic zircon. Titanium measurements ( n = 158) yield a mean Ti concentration of 11.7 ± 6.1 ppm (2SD) which corresponds to a mean crystallization temperature of 790°C for an α-TiO2 = 0.74 (estimated using mineral equilibria), or 760°C for an α-TiO2 = 1.0. Apparent zircon crystallization temperatures are similar in all intrusive phases, although the gabbro yields slightly higher values, indicating that crystallization occurred at the same temperature in all rock types. This finding is consistent with previous work on the BPZP, which indicates that liquid-crystal sorting (crystal fractionation) was the dominant control on chemical differentiation, and that late, differentiated liquids were similar in composition for all rock types. A simple forward model approximately predicts the range of crystallization temperatures, but not the shape of the distributions, due to sampling biases and complexities in the cooling and crystallization history of the pluton. The distribution of Ti concentrations has a mode at a higher Ti (higher temperature) than the sample set of Hadean detrital zircon. This is consistent with the hypothesis that the skew to low-T in the Hadean dataset is due to the presence of zircon that crystallized from wet anatectic melts.

  8. Mineralogy, geochemistry, and evolution of the Mivehrood skarn and the associated pluton, northwest Iran

    NASA Astrophysics Data System (ADS)

    Alirezaei, Saeed; Einali, Morteza; Jones, Peter; Hassanpour, Shohreh; Arjmandzadeh, Reza

    2016-04-01

    An Upper Miocene (9.12 ± 0.19 Ma; biotite 40Ar/39Ar) shallow pluton and numerous dykes and sills of felsic-intermediate compositions intruded the Upper Cretaceous, flysch-type sediments in the Mivehrood area, northwest Iran. The intrusions caused extensive thermal metamorphism and metasomatism, leading to the formation of hornfels and skarn. A massive skarn, 1-10 m thick, immediate to the intrusive contact, is bordered by a banded skarn, 100-400 m thick, that grades outward into hornfels and original sediments. The Mivehrood pluton is characterized by steep REE pattern, high Al2O3 (14.64-16.4 wt%) and Sr (380-786 ppm), and low MgO (1.3-3.4 wt%), Y (4.8-10.7 ppm), and Yb (0.35-0.95 ppm), characteristics typical of high-silica adakites. Skarn formation started with thermal metamorphism, followed by anhydrous prograde and hydrous retrograde stages. Prograde and retrograde mineral assemblages are developed in both skarns, represented by garnet-clinopyroxene-wollastonite and epidote-actinolite-scapolite-chlorite, respectively. Granditic F-bearing garnet dominates clinopyroxene in both skarns. The banded skarn contains minor scapolite of marialite composition. The calc-silicate mineral assemblages and the mineral chemistry allow the Mivehrood skarn to be classified as a calcic, oxidized skarn. Mass balance assessments suggest that Fe, Si, and S were significantly enriched, and Na, LILEs, and LREEs were strongly depleted, in the massive skarn. In the banded skarn, Na, K, Si, and S were enriched. Significant dehydration and carbon degassing occurred in both skarns. Stockworks, veins, and replacement bodies of pyrite ± chalcopyrite locally occur in the pluton and the dykes and in the skarns. The δ34SCDT values for the sulfides fall in a narrow range around 0.0 ‰, suggesting a magmatic source for sulfur and possibly the hydrothermal water and solutes involved in the skarn formation.

  9. Source variation for Mesozoic granitoid plutons in the White-Inyo Range, California, and implications for changes in the lithospheric structure

    NASA Astrophysics Data System (ADS)

    Gammel, E.; Nabelek, P. I.; Phillips, E. H. W.; Scott, S. R.; Sims, K. W. W.

    2015-12-01

    The White-Inyo Range (WIR) of eastern California lies to the east of Owen's Valley and the Sierra Nevada batholith (SNB). Over twenty recognized Mesozoic, granitic to gabbroic plutons intruded into Precambrian and Cambrian sedimentary units that were previously metamorphosed to the greenschist facies. These plutons represent intrusive equivalents of volcanics erupted during two magmatic events at ca. 180-167 Ma and 102-86 Ma (Coleman et al, 2003). The motivation of this study is to understand changes in magma sources over this time period. We propose there is a time-transgressive change in source material in the WIR. Preliminary trace element data suggest that Jurassic plutons were sourced from deep crustal material, whereas later Cretaceous plutons may have had a shallower origin. This is supported by high Sr/Y ratios in the Jurassic plutons (up to 300) and relatively lower ratios in Cretaceous plutons (down to 14). Chiaradia (2015) suggests elevated Sr/Y ratios are directly linked to increasing crustal thickness, therefore the WIR plutons may record the period of crustal thinning in this region or maturation of the crust that allowed shallower melting in the Cretaceous. The highest values also suggest possible adakitic source material. REE patterns suggest that the youngest plutons (e.g. Sage Hen Flat) are more similar to samples collected from the eastern Sierra Nevada batholith than older plutons with higher La/Yb ratios. Relatively flat patterns REE patterns of Tertiary basalts and a late diabase dike in the WIR are also similar to SNB samples. Another goal of this study is to determine the degree of mixing as a function of time during the emplacement of plutons in the range. Field and petrographic analyses suggest that older plutons represent more mafic materials and younger plutons are more granitic with mafic enclaves. We propose either (1) older plutons represent initial lower lithosphere melting, and with time, there is an increase of incorporation of

  10. Ductile strain rate recorded in the Symvolon syn-extensional plutonic body (Rhodope core complex, Greece)

    NASA Astrophysics Data System (ADS)

    Cirrincione, Rosolino; Fazio, Eugenio; Ortolano, Gaetano; Fiannacca, Patrizia; Kern, Hartmut; Mengel, Kurt; Pezzino, Antonino; Punturo, Rosalda

    2016-04-01

    The present contribution deals with quantitative microstructural analysis, which was performed on granodiorites of the syn-tectonic Symvolon pluton (Punturo et al., 2014) at the south-western boundary of the Rhodope Core Complex (Greece). Our purpose is the quantification of ductile strain rate achieved across the pluton, by considering its cooling gradient from the centre to the periphery, using the combination of a paleopiezometer (Shimizu, 2008) and a quartz flow law (Hirth et al., 2001). Obtained results, associated with a detailed cooling history (Dinter et al., 1995), allowed us to reconstruct the joined cooling and strain gradient evolution of the pluton from its emplacement during early Miocene (ca. 700°C at 22 Ma) to its following cooling stage (ca. 500-300°C at 15 Ma). Shearing temperature values were constrained by means of a thermodynamic approach based on the recognition of syn-shear assemblages at incremental strain; to this aim, statistical handling of mineral chemistry X-Ray maps was carried out on microdomains detected at the tails of porphyroclasts. Results indicate that the strain/cooling gradients evolve "arm in arm" across the pluton, as also testified by the progressive development of mylonitic fabric over the magmatic microstructures approaching the host rock. References • Dinter, D. A., Macfarlane, A., Hames, W., Isachsen, C., Bowring, S., and Royden, L. (1995). U-Pb and 40Ar/39Ar geochronology of the Symvolon granodiorite: Implications for the thermal and structural evolution of the Rhodope metamorphic core complex, northeastern Greece. Tectonics, 14 (4), 886-908. • Shimizu, I. (2008). Theories and applicability of grain size piezometers: The role of dynamic recrystallization mechanisms. Journal of Structural Geology, 30 (7), 899-917. • Hirth, G., Teyssier, C., and Dunlap, J. W. (2001). An evaluation of quartzite flow laws based on comparisons between experimentally and naturally deformed rocks. International Journal of Earth

  11. Statistical analysis of slab-window related plutons: The Sanak-Baranof belt of southern Alaska

    NASA Astrophysics Data System (ADS)

    Farris, D. W.; Paterson, S.

    2002-12-01

    The Sanak-Baranof belt of southern Alaska is a chain of near-trench plutons that formed during the subduction of a spreading-ridge and the subsequent formation of a slab-window. Intrusions within this belt have a time-transgressive distribution that ranges from 61-50 Ma over its 2100 km length, and they are thought to track the movement of the ridge-trench-trench triple junction and the slab-window. We analyzed the spatial distribution, the orientation and the frequency-size statistics of 64 plutons within the Sanak-Baranof belt. These data indicate that intrusions within the Sanak-Baranof belt have a power-law frequency-size distribution. The power-law has the form N~A{ -0.76} +/-0.15 which is quite similar to that calculated for other magmatic systems (Pelletier, 1999). We hypothesize that such a distribution is related to how magma propagates through the crust, which is similar for both the Sanak-Baranof belt and `normal' arc environments. A statistical analysis of the spatial relationships of the Sanak-Baranof belt plutons indicate that magmatism has a uniform nearest-neighbor distribution at the scale of individual plutons, but is clustered at scales larger than 100-200 km. One interpretation is that the spacing of magmatic centers is related to segmentation of the subducting ridge. However, between the western and eastern portions of the Sanak-Baranof belt there is a change in the spacing of magmatic centers. In the western portion, magmatic centers have a spacing of approximately 165 km, whereas in the east (within the Chugach metamorphic complex), magmatism is continuous at the scale of our analysis. We hypothesize that in the western portion of the belt the subducting spreading-ridge was oriented at an oblique angle (30°) to the trench, and the triple junction was migrating rapidly to the east at 19 cm/yr. In the eastern portion of the Sanak-Baranof belt, the trailing edge of the plate was parallel to the subduction zone causing the rate of spreading

  12. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  13. Grace DAKASEP alkaline battery separator

    NASA Technical Reports Server (NTRS)

    Giovannoni, R. T.; Lundquist, J. T.; Choi, W. M.

    1987-01-01

    The Grace DAKASEP separator was originally developed as a wicking layer for nickel-zinc alkaline batteries. The DAKASEP is a filled non-woven separator which is flexible and heat sealable. Through modification of formulation and processing variables, products with a variety of properties can be produced. Variations of DAKASEP were tested in Ni-H2, Ni-Zn, Ni-Cd, and primary alkaline batteries with good results. The properties of DAKASEP which are optimized for Hg-Zn primary batteries are shown in tabular form. This separator has high tensile strength, 12 micron average pore size, relatively low porosity at 46-48 percent, and consequently moderately high resistivity. Versions were produced with greater than 70 percent porosity and resistivities in 33 wt percent KOH as low as 3 ohm cm. Performance data for Hg-Zn E-1 size cells containing DAKASEP with the properties shown in tabular form, are more reproducible than data obtained with a competitive polypropylene non-woven separator. In addition, utilization of active material is in general considerably improved.

  14. Holocene climate variability on the Kola Peninsula, Russian Subarctic, based on aquatic invertebrate records from lake sediments

    NASA Astrophysics Data System (ADS)

    Ilyashuk, Elena A.; Ilyashuk, Boris P.; Kolka, Vasily V.; Hammarlund, Dan

    2013-05-01

    Sedimentary records of invertebrate assemblages were obtained from a small lake in the Khibiny Mountains, Kola Peninsula. Together with a quantitative chironomid-based reconstruction of mean July air temperature, these data provide evidence of Holocene climate variability in the western sector of the Russian Subarctic. The results suggest that the amplitude of climate change was more pronounced in the interior mountain area than near the White Sea coast. A chironomid-based temperature reconstruction reflects a warming trend in the early Holocene, interrupted by a transient cooling at ca. 8500-8000 cal yr BP with a maximum drop in temperature (ca. 1°C) around 8200 cal yr BP. The regional Holocene Thermal Maximum, characterized by maximum warmth and dryness occurred at ca. 7900-5400 cal yr BP. During this period, July temperatures were at least 1°C higher than at present. The relatively warm and dry climate persisted until ca. 4000 cal yr BP, when a pronounced neoglacial cooling was initiated. Minimum temperatures, ca. 1-2°C lower than at present, were inferred at ca. 3200-3000 cal yr BP. Faunal shifts in the stratigraphic profile imply also that the late-Holocene cooling was followed by a general increase in effective moisture.

  15. Emission of CO2 by soils in the impact zone of the Severonikel smelter in the Kola subarctic region

    NASA Astrophysics Data System (ADS)

    Kadulin, M. S.; Koptsik, G. N.

    2013-11-01

    The intensity of the in situ soil respiration in the background northern taiga spruce forests of the Kola subarctic region reaches 120-290 mg C-CO2/m2 per h. In the impact zone of the Severonikel smelter, it decreases to 90-140, 30, and 15-30 mg C-CO2/m2 per h at the stages of spruce defoliation, spruce-birch woodland, and technogenic barrens of the technogenic succession, respectively. For the first time, the impact of the industrial pollution on root respiration has been assessed, and the dependences of the CO2 emission, the contribution of mineral soil horizons to this process, the microbial biomass, and root respiration on the concentrations of available nickel and copper compounds have been determined. The efficiency of two remediation technologies applied to technogenic barrens near the smelter has been evaluated on the basis of four parameters of the soil biological activity. The results indicate that remediation with the creation of a new filled soil layer is more efficient than chemical and phytoremediation methods.

  16. Emissions from the copper-nickel industry on the Kola Peninsula and at Noril'sk, Russia

    USGS Publications Warehouse

    Boyd, Ron; Barnes, S.-J.; De Caritat, P.; Chekushin, V.A.; Melezhik, V.A.; Reimann, C.; Zientek, M.L.

    2009-01-01

    Published estimates for base metal emissions from the copper-nickel industry on the Kola Peninsula are re-examined in the light of (a) chemical data on the composition of the ores; (b) official emission figures for 1994; and (c) modelled emissions based on dry and wet deposition estimates derived from data for snow and rain samples collected in 1994. The modelled emissions, official emission figures and chemical data are mutually compatible for Ni, Cu and Co and show that previously published figures underestimated the emissions of the major elements, Ni and Cu (though within the same order of magnitude) and overestimated the emissions of As, Pb, Sb and Zn by up to several orders of magnitude, in some cases exceeding the calculated total input to the plants. Published estimates have neglected information on the nature and chemistry of the ores processed in metallurgical industries in the Noril'sk area of Siberia and the Urals. Revised emission estimates for 1994, using knowledge of the chemistry of the ores, are proposed: taken with published information on total emissions up to 2000 these data give an indication of emission levels in more recent years. ?? 2008 Elsevier Ltd. All rights reserved.

  17. Autumn migration and wintering areas of Peregrine Falcons Falco peregrinus nesting on the Kola Peninsula, northern Russia

    USGS Publications Warehouse

    Ganusevich, S.A.; Maechtle, T.L.; Seegar, W.S.; Yates, M.A.; McGrady, M.J.; Fuller, M.; Schueck, L.; Dayton, J.; Henny, C.J.

    2004-01-01

    Four female Peregrine Falcons Falco peregrinus breeding on the Kola Peninsula, Russia, were fitted with satellite-received transmitters in 1994. Their breeding home ranges averaged 1175 (sd = ??714) km2, and overlapped considerably. All left their breeding grounds in September and migrated generally south-west along the Baltic Sea. The mean travel rate for three falcons was 190 km/day. Two Falcons wintered on the coasts of France and in southern Spain, which were, respectively, 2909 and 4262 km from their breeding sites. Data on migration routes suggested that Falcons took a near-direct route to the wintering areas. No prolonged stopovers were apparent. The 90% minimum convex polygon winter range of a bird that migrated to Spain encompassed 213 km2 (n = 54). The area of the 50% minimum convex polygon was 21.5 km2 (n = 29). Data from this study agree with others from North America that show that Falcons breeding in a single area do not necessarily follow the same migratory path southward and do not necessarily use the same wintering grounds.

  18. Alkaline and alkaline earth metal phosphate halides and phosphors

    SciTech Connect

    Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

    2012-11-13

    Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

  19. Relationships between subduction and extension in the Aegean region: evidence from granite plutons of the Biga Peninsula, NW Turkey

    NASA Astrophysics Data System (ADS)

    Black, K. N.; Catlos, E. J.; Oyman, T.; Demirbilek, M.

    2012-04-01

    The Biga Peninsula is a tectonically complex region in western Turkey characterized by Tethyan sutures overprinted by extensional grabens, active fault strands of the North Anatolian Shear Zone, and numerous granitoid plutons. Two end-member models for the initiation of extension in the Biga region have been proposed, both of which focus on the role of igneous assemblages. The first model involves the emplacement of a hot mantle plume that thins and weakens crust and isostatic doming drives extension. The second has regional tensional stresses as the driving force, and magmatism is a consequence of decompression. Here we focus on understanding the timing and geochemical evolution of three granitoid plutons located in and just south of the Biga Peninsula to understand which end-member model could be applicable to the Aegean region. The Kestanbolu pluton is located north of the proposed Vardar Suture Zone, whereas the Eybek and Kozak plutons are north of the Izmir-Ankara Suture Zone. These sutures may mark regions of the closure of branches of the NeoTethyan Ocean. To better understand their sources and tectonic evolution, we acquired geochemical and geochronological data, and cathodoluminescence (CL) images of the rocks. Previously reported ages of the plutons range from Late Eocene to Middle Miocene. Here we acquired in situ (in thin section) ion microprobe U-Pb ages of zircon grains found in a range of textural relationships. Ages from the Kozak pluton range from 37.8±5.4 Ma to 10.3±2.4 Ma (238U/206Pb, ±1σ) with two ages from a single grain of 287±26 Ma and 257±18 Ma. We also found Oligocene to Late Miocene zircon grains in the Kestanbolu pluton, whereas zircons from the Eybek pluton range from 34.3±4.8 Ma to 21.2±1.7 Ma. Samples collected from the Kozak and Eybek plutons are magnesian, calc-alkalic, and metaluminous, whereas the Kestanbolu rocks are magnesian, alkali-calcic, and metaluminous with one ferroan sample and one peraluminous sample. Trace

  20. Pluton accommodation at high strain rates in the upper continental crust. The example of the Central Extremadura batholith, Spain

    NASA Astrophysics Data System (ADS)

    Fernández, Carlos; Castro, Antonio

    1999-08-01

    Emplacement in the tensional bridge of a stepped dextral shear zone system is proposed for the Central Extremadura batholith (Spain). The country rocks show a pervasive anisotropy that conditioned the style of the structures developed as a consequence of the transference of displacement from the stepped shear zones to the releasing area. The kinematic evolution of the resulting megakink fold provided the volume increase necessary for the granite emplacement. Thermal and kinematic models suggest that the growth of individual plutons took place in periods of no more than several hundred to a few thousand years. Fast strain rates (10 -10-10 -11 s -1) must concentrate in local structures (e.g. initiation of kink folds) even in zones deforming as a whole under typical strain rates (10 -14±1 s -1). Granite plutons might be used as strain-rate gauges for syn-plutonic structures.

  1. Investigation of the mineral potential of the Clipper Gap, Lone Mountain-Weepah, and Pipe Spring plutons, Nevada

    SciTech Connect

    Tingley, J.V.; Maldonado, F.

    1983-09-15

    The Clipper Gap pluton, composed mostly of quartz monzonite with minor granite, granodiorite, and crosscutting alaskite dikes, intrudes Paleozoic western facies strata. A narrow zone of contact metamorphism is present at the intrusive-sediment contact. No mineral production has been recorded from Clipper Gap, but quartz veins containing gold-silver-copper mineral occurrences have been prospected there from the late 1800's to the present. Areas of the Lone Mountain-Weepah plutons that were studied are located in Esmeralda County about 14 km west of Tonopah, Nevada. At Lone Mountain, a Cretaceous intrusive cuts folded Precambrian and Cambrian sediments. Lead-zinc ores have been mined from small replacement ore bodies in the Alpine district, west of Lone Mountain. Copper and molybdenum occurrences have been found along the east flank of Lone Mountain, and altered areas were noted in intrusive outcrops around the south end of Lone Mountain. Mineral occurrences are widespread and varied with mining activity dating back to the 1860's. The Pipe Spring pluton study area is flanked by two important mining districts, Manhattan to the north and Belmont to the northeast. Mining activity at Belmont dates from 1865. Activity at Manhattan was mainly between 1907 and 1947, but the district is active at the present time (1979). Four smaller mining areas, Monarch, Spanish Springs, Baxter Spring, and Willow Springs, are within the general boundary of the area. The Pipe Spring pluton study area contains numerous prospects along the northern contact zone of the pluton. Tungsten-bearing veins occur within the pluton near Spanish Springs, with potential for gold-tungsten placer in the Ralston Valley. Nickel and associated metals occur at Willow Spring and Monarch Ranch, where prospects may be associated with the margin of the Big Ten Peak Caldera.

  2. Melt Extraction Zones in Shallow Arc Plutons: Insights from Fisher Lake Orbicules and Comb Layers, Northern Sierra Nevada

    NASA Astrophysics Data System (ADS)

    McCarthy, A. J.; Muntener, O.

    2015-12-01

    Identifying the processes behind magma flow structures and complex sheeted zones within otherwise near-homogeneous shallow plutons is fundamental in order to understand the mechanisms of melt transport, magma differentiation, crustal recycling and growth of mid-upper crustal plutons. The Cretaceous gabbro-diorite pluton of Fisher Lake, Northern Sierra Nevada (USA), contains multiple m-sized orbicule and magma-breccia bodies as well as orbicule- and comb layer-bearing dikes. Olivine-bearing norites, hornblende diorites and gabbros which have crystallized at low pressure (2kbar) from hydrous basaltic-andesite melts form texturally diverse orbicule cores which act as nuclei for comb layers. Rising hydrous mafic melts remobilizing low pressure cumulates and/or crystal mushes are injected at the contact between cooling plutons prior to the initiation of comb layer growth. Multiple generations of melt injections are attested by the presence of magma-breccia bodies which incorporate fractured, disaggregated fragments of pre-existing orbicule and comb layer bodies. The cumulate signature of the orbicule-bearing matrix indicates that interstitial melt was extracted towards shallower depth. Though orbicule and comb layer bodies have been variously ascribed to melt migration within cooling plutons, magma mixing or fluid flow, we propose an alternative interpretation where these m-scale features represent localized subvertical channels formed during the extraction of multiple batches of hydrous melts within a volcanic plumbing system or shallow plutonic feeder zone. These features thus preserve unique evidence of upper-crustal melt migration processes during the transfer of hydrous mafic melts towards shallower depth. Geochemical gradients between decompressing liquids and crystallizing cumulates are the main driving force for crystallization. We will illustrate examples of this process on the basis of field observations, textural data, whole rock and mineral geochemistry.

  3. Open-System Alkaline Magmatism in the Caledonides of North-Central Norway

    NASA Astrophysics Data System (ADS)

    Barnes, C. G.; Prestvik, T.; Barnes, M. A.

    2002-12-01

    The Caledonian-age Hortavaer intrusion is exposed on small islands and skerries off the coast of north-central Norway. It was emplaced into a range of host rocks that includes calcitic and dolomitic marble to migmatitic gneiss to quartz-rich meta-arenite. The intrusion is unusual relative to Caledonian plutons on the mainland because of its alkaline nature and its possible circa 460-470 Ma age (based on imprecise Sr and Nd isochrones). The intrusion is broadly zoned, with central diorite and outer syenite. Dike-like bodies of monzonite and syenite are also present and are elongate in a NNE-SSW direction. Each lithologic unit is characterized by evidence for magma mingling, particularly by synplutonic dikes and enclaves. In the syenitic zone, mingled magmas ranged from monzonitic (syenitic) to dioritic. In the diorite zone, mingling was dominated by diorite-in-diorite, but composite diorite-syenite dikes are present. The contact between the syenite and diorite units is marked by an approximately 500-m-wide zone of sheeted diorite/syenite dikes that are mutually intrusive. In addition to magma mingling, the complex shows a variety of types of interaction with screens of its host rocks, which are typically subparallel to foliation in the pluton. Some screens were apparently unreactive with the surrounding magma, whereas others resulted in intense reaction and formation of garnet melasyenite, pyroxene-rich monzodiorite, and rare nepheline-bearing rocks. A trend toward Fe enrichment among the dioritic rocks, the low Mg/(Mg+Fe) and Sr contents of the evolved syenites, and curvilinear composition trends for many elements in the suite suggest fractional crystallization was a major control on magma evolution. However, low epsilon Nd (465 Ma) (-3 to -10), moderate initial 87Sr/86Sr (0.705 to 0.710), and high delta18O (+8.3 to +14.0 %) suggest either a crustal source or intense contamination. The presence of primary calcite with delta13C typical of host carbonate rocks

  4. A reassessment of models for hydrocarbon generation in the Khibiny nepheline syenite complex, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Beeskow, B.; Treloar, P. J.; Rankin, A. H.; Vennemann, T. W.; Spangenberg, J.

    2006-10-01

    Although hydrocarbon-bearing fluids have been known from the alkaline igneous rocks of the Khibiny intrusion for many years, their origin remains enigmatic. A recently proposed model of post-magmatic hydrocarbon (HC) generation through Fischer-Tropsch (FT) type reactions suggests the hydration of Fe-bearing phases and release of H 2 which reacts with magmatically derived CO 2 to form CH 4 and higher HCs. However, new petrographic, microthermometric, laser Raman, bulk gas and isotope data are presented and discussed in the context of previously published work in order to reassess models of HC generation. The gas phase is dominated by CH 4 with only minor proportions of higher hydrocarbons. No remnants of the proposed primary CO 2-rich fluid are found in the complex. The majority of the fluid inclusions are of secondary nature and trapped in healed microfractures. This indicates a high fluid flux after magma crystallisation. Entrapment conditions for fluid inclusions are 450-550 °C at 2.8-4.5 kbar. These temperatures are too high for hydrocarbon gas generation through the FT reaction. Chemical analyses of rims of Fe-rich phases suggest that they are not the result of alteration but instead represent changes in magma composition during crystallisation. Furthermore, there is no clear relationship between the presence of Fe-rich minerals and the abundance of fluid inclusion planes (FIPs) as reported elsewhere. δ 13C values for methane range from - 22.4‰ to - 5.4‰, confirming a largely abiogenic origin for the gas. The presence of primary CH 4-dominated fluid inclusions and melt inclusions, which contain a methane-rich gas phase, indicates a magmatic origin of the HCs. An increase in methane content, together with a decrease in δ 13C isotope values towards the intrusion margin suggests that magmatically derived abiogenic hydrocarbons may have mixed with biogenic hydrocarbons derived from the surrounding country rocks.

  5. Syn-extensional plutonism and peak metamorphism in the albion-raft river-grouse creek metamorphic core complex

    USGS Publications Warehouse

    Strickland, A.; Miller, E.L.; Wooden, J.L.; Kozdon, R.; Valley, J.W.

    2011-01-01

    The Cassia plutonic complex (CPC) is a group of variably deformed, Oligocene granitic plutons exposed in the lower plate of the Albion-Raft River- Grouse Creek (ARG) metamorphic core complex of Idaho and Utah. The plutons range from granodiorite to garnet-bearing, leucogranite, and during intrusion, sillimanite- grade peak metamorphism and ductile attenuation occurred in the country rocks and normal-sense, amphibolite-grade deformation took place along the Middle Mountain shear zone. U-Pb zircon geochronology from three variably deformed plutons exposed in the lower plate of the ARG metamorphic core complex revealed that each zircon is comprised of inherited cores (dominantly late Archean) and Oligocene igneous overgrowths. Within each pluton, a spread of concordant ages from the Oligocene zircon overgrowths is interpreted as zircon recycling within a long-lived magmatic system. The plutons of the CPC have very low negative whole rock ??Nd values of -26 to -35, and initial Sr values of 0.714 to 0.718, consistent with an ancient, crustal source. Oxygen isotope ratios of the Oligocene zircon overgrowths from the CPC have an average ??18O value of 5.40 ?? 0.63 permil (2SD, n = 65) with a slight trend towards higher ??18O values through time. The ??18O values of the inherited cores of the zircons are more variable at 5.93 ?? 1.51 permil (2SD, n = 29). Therefore, we interpret the plutons of the CPC as derived, at least in part, from melting Archean crust based on the isotope geochemistry. In situ partial melting of the exposed Archean basement that was intruded by the Oligocene plutons of the CPC is excluded as the source for the CPC based on field relationships, age and geochemistry. Correlations between Ti and Hf concentrations in zircons from the CPC suggest that the magmatic system may have become hotter (higher Ti concentration in zircon) and less evolved (lower Hf in zircon concentration) through time. Therefore, the CPC represents prolonged or episodic magmatism

  6. Emplacement and geochemical evolution of eocene plutonic rocks in the Colville batholith

    SciTech Connect

    Holder, R.W.

    1986-01-01

    Eocene plutonic rocks in the Colville batholith are divided on the basis of field evidence and chemical composition into, in order of decreasing age, (1) several calc-alkalic biotite-hornblende monzodiorite to granodiorite intrusions referred to as the Devils Elbow suite, and (2) compositionally variable calc-alkalic to alkali-calcic intrusions referred to as the Herron Creek suite. These Eocene suites are distinct from older, more voluminous, leucocratic granite and granodiorite intrusions, designated the Keller Butte suite, which are calcic and characteristically lack hornblende. Results of qualitative and computer modeling of major element variation and quantitative models of trace element variation in the chemically coherent Bridge Creek intrusions, a member of the Herron Creek suite, are compatible with fractionation of plagioclase feldspar + hornblende + biotite + magnetite + apatite from a parent magma of andesitic composition to account for the observed variation. Strongly curved variation trends preclude mixing as the primary mechanism for the observed variation. It is suggested that parallel variation trends in the other Eocene intrusions are also the result of crystal fractionation. Lateral chemical variations including a decrease in silica saturation suggest the chemical characteristics of these rocks reflect those of parental magmas derived from the mantle, with an unknown amount of crustal contribution. Rotated and angular xenoliths, discordant contacts, and temporal and spatial proximity to graben structures indicate that the Eocene plutons were passively implaced into the upper crust along graben-bounding faults during graben formation, the earlier stages of which appear to have been contemporaneous with regional mylonitic deformation.

  7. Mingled mafic and felsic magmas in the Jurassic Eagle Mountain pluton, southeastern California

    SciTech Connect

    Mayo, D.P. . Dept. of Geological Sciences); Wooden, J.L. )

    1993-04-01

    The metalluminous, compositionally expanded Eagle Mountain pluton ([approx] 165 Ma) was epizonally emplaced within Proterozoic metaigneous and Proterozoic-Paleozoic metasedimentary rocks in the Eagle Mountains of southeastern California. The evolution of the pluton involved mingling and partial mixing between mafic and felsic magmas. Heterogeneous rocks consisting of discrete biotite-clinopyroxene microdioritic enclaves (49--54% SiO[sub 2]) enclosed in hornblende-biotite granodiorite (57--61% SiO[sub 2]) grade into complexly mingled microdiorite and granodiorite as the proportion of microdiorite increases. The dioritic enclaves are notably potassic (2.1 [+-] .2 wt. %), containing abundant biotite (up to 23%) and interstitial patches of K-feldspar. These features are attributed to selective potassium enrichment of dioritic magma by diffusion during mingling with host granodioritic magma. A similar phenomenon was observed in experiments by Johnston and Wyllie, and attributed to relatively rapid diffusion of potassium from felsic to mafic magma. Calculated Sr[sub i] for the enclaves, intermediate dioritoids, and three of four analyzed host rocks cluster at 0.7085 [+-] 0.0002. Several homogeneous monzogranites not associated with enclaves have slightly higher Sr[sub i] (up to 0.7094) and define two separate mixing/AFC arrays on a plot of Sr[sub i] vs. 1/Sr, both anchored at the cluster of less radiogenic rocks. Alternatively, relatively rapid self-diffusion of Sr may have contributed to isotopic homogeneity during mingling of magmas from isotopically distinct sources.

  8. Magma accumulation rates and thermal histories of plutons of the Sierra Nevada batholith, CA

    NASA Astrophysics Data System (ADS)

    Davis, Jesse W.; Coleman, Drew S.; Gracely, John T.; Gaschnig, Richard; Stearns, Michael

    2012-03-01

    Zircon U-Pb geochronology results indicate that the John Muir Intrusive Suite of the central Sierra Nevada batholith, California, was assembled over a period of at least 12 Ma between 96 and 84 Ma. Bulk mineral thermochronology (U-Pb zircon and titanite, 40Ar/39Ar hornblende and biotite) of rocks from multiple plutons comprising the Muir suite indicates rapid cooling through titanite and hornblende closure following intrusion and subsequent slow cooling through biotite closure. Assembly of intrusive suites in the Sierra Nevada and elsewhere over millions of years favors growth by incremental intrusion. Estimated long-term pluton assembly rates for the John Muir Intrusive Suite are on the order of 0.001 km3 a-1 which is inconsistent with the rapid magma fluxes that are necessary to form large-volume magma chambers capable of producing caldera-forming eruptions. If large shallow crustal magma chambers do not typically develop during assembly of large zoned intrusive suites, it is doubtful that the intrusive suites represent cumulates left behind following caldera-forming eruptions.

  9. Rates of Magma Transfer in the Crust: Insights into Magma Reservoir Recharge and Pluton Growth

    NASA Astrophysics Data System (ADS)

    Menand, T.; Annen, C.; De Saint Blanquat, M.

    2014-12-01

    Plutons have long been viewed as crystallized remnants of large magma reservoirs, a concept now challenged by high precision geochronological data coupled with thermal models. Similarly, the classical view of silicic eruptions fed by long-lived magma reservoirs that slowly differentiate between mafic recharges is being questioned by petrological and geophysical studies. In both cases, a key and yet unresolved issue is the rate of magma transfer in the crust. Here, we use thermal analysis of magma transport to calculate the minimum rate of magma transfer through dykes. We find that unless the crust is exceptionally hot the recharge of magma reservoirs requires a magma supply rate of at least ~ 0.01 km3/yr, much higher than the long-term growth rate of plutons, which demonstrates unequivocally that igneous bodies must grow incrementally. This analysis argues also for magma reservoirs being short-lived and erupting rapidly after a recharge of already differentiated magma. These findings have strong implications for the monitoring of dormant volcanic systems, and raise questions on our ability to interpret geodetic surface signals related to incipient eruptions.

  10. The gabbro (shoshonitic)-monzonite-granodiorite association of Khankandi pluton, Alborz Mountains, NW Iran

    NASA Astrophysics Data System (ADS)

    Aghazadeh, Mehraj; Castro, Antonio; Omran, Nematallah Rashidnejad; Emami, Mohamad Hashem; Moinvaziri, Hossien; Badrzadeh, Zahra

    2010-05-01

    The Khankandi pluton forms part of a group of gabbro-granodiorite intrusions in the Alborz Mountains of NW Iran. A petrographical and geochemical study of this plutonic association reveals the existence of several magmatic cycles with different origins and slight differences in age. The oldest cycle (C1) is represented by granodiorites. A second cycle (C2) is formed by a gabbro-monzonite association, with a clear shoshonitic affinity, that dominates most of the intrusive volume. Gabbros and monzonites form a co-magmatic association. Zircons from the monzonites were analyzed by LA-ICP-MS for U-Pb dating. An average age of 28.9 Ma, ranging from 23.7 to 33.6 Ma was obtained. Gabbros, monzonites and granodiorites share a nearly common isotopic ratio for Sr and Nd. Both initial Sr and Nd ratios are clustered within a narrow range from 0.7045 to 0.7047 for the 87Sr/ 86Sr ratio and ɛNd from 1.46 to 1.89. Comparison with experimental studies, together with mantle-like isotopic ratios and comparisons of REE patterns, points to an origin by variable melting rates from a common metasomatised mantle source for gabbros and monzonites. Melting of a subducted mélange is suggested for the granodiorite magmas predating the gabbro-monzonite intrusion. The two sources, a metasomatised mantle and ascending silicic plumes, are direct consequence of subduction.

  11. A possible concealed pluton in Beaverhead and Madison Counties, Montana, and Clark County, Idaho

    USGS Publications Warehouse

    Witkind, Irving Jerome

    1974-01-01

    A northeast-trending magnetic anomaly in parts of Beaverhead and Madison Counties, Mont., and Clark County, Idaho, may reflect the trend, shape, and size of a concealed pluton. The type of rock that forms the pluton(?) is unknown. A small volcanic pipe, possibly a diatreme, is at the southeast end of the high. The pipe, about 92 m (300 ft) in diameter, consists of a rubbly basalt-like matrix through which are scattered xenoliths of Precambrian crystalline rocks and of various Paleozoic and Mesozoic strata. It is uncertain whether the juxtaposition of the pipe and the magnetic high is meaningful or is merely fortuitous. Although no mineralized rock was found in the area underlain by the anomaly, placer gold has been found nearby. Some 113 km (70 mi) to the west, in Custer and Lemhi Counties, Idaho, a similar northeast-trending magnetic high marks the site of the Gilmore mining district. The similarities in trend, shape, and magnitude between the two anomalies suggest that the high in Beaverhead and Madison Counties should be investigated for undetected mineral deposits, possibly by a geochemical survey.

  12. Reworked old crust-derived shoshonitic magma: The Guarany pluton, Northeastern Brazil

    NASA Astrophysics Data System (ADS)

    Ferreira, Valderez P.; Sial, Alcides N.; Pimentel, Marcio M.; Armstrong, Richard; Guimarães, Ignez P.; da Silva Filho, Adejardo F.; de Lima, Mariucha Maria C.; da Silva, Thyego R.

    2015-09-01

    The 572 Ma Guarany stock consists of magmatic epidote-bearing hornblende monzodiorite to biotite granite that intruded Paleoproterozoic orthogneisses about 10 km inland from the coast in northeastern Brazil. Co-magmatic diorite enclaves and dikes are abundant throughout the pluton. The monzodiorite-granite pluton and diorite enclaves are shoshonitic and display continuous trends in variation diagrams. They display chemical and isotopic characteristics of crustal melts, such as enrichment in incompatible elements, high back-calculated initial 87Sr/86Sr ratios (avg. 0.71253), negative εNd (0.57Ga) values (avg. - 14.58), as well as high and variable (+ 9.1 to + 11.1‰VSMOW) δ18O (zircon) values. Correlations between O-isotope and whole-rock silica contents, as well as initial 87Sr/86Sr ratios with 1/Sr concentrations, suggest hybridization of a lower continental crustal melt with more felsic crustal rocks, concomitant with fractional crystallization. Amphibole chemistry and whole rock Zr, TiO2 and P2O5 contents suggest magma solidification at a pressure ~ 7 kbar and near liquidus temperature ~ 900 °C. The parental magma was likely formed by partial melting of old (tDM = 2.0 Ga) amphibolitic lower continental crustal rocks, in a post-collisional setting, probably triggered by underplating of mantle-derived mafic magma during the period of relaxation after collision.

  13. Calc-alkaline mafic rocks of the Black Dyke Formation: Remnants of the final activity of a submerged Permian volcano

    SciTech Connect

    Blein, O.; Lapierre, H.; Pecher, A. ); Schweickert, R.A. . Dept. of Geological Science)

    1993-04-01

    The Permian Black Dyke Fm., which occurs as large tectonic slices within the Luning allochthon in the Excelsior Mountains, NV, forms an E-W trending anticline at Black Dyke Mountain. The 800-m thick stratigraphic succession consists of volcanic and pyroclastic rocks overlain conformably by volcaniclastic sediments. Along the northern limb of the anticline, the rocks consist of mafic porphyritic lavas, breccias, and graded and ungraded pyroclastic beds. The sedimentary unit consists of thick volcaniclastic turbidites overlain by conglomerates, sandstones, and mudstones. Along the southern limb of the anticline, the sequence is replaced by reworked breccia, tuffs, and sandstones. Mafic plutonic rocks occur as xenoliths in the lavas and breccias, and as coeval plugs intruding the section. Gabbros show cumulate or porphyritic textures and are composed of amph, cpx, and zoned plag. Their Ti/V (14.5--15) and Nb/Y (0.25--0.3) ratios fall in the range commonly found in calc-alkaline rocks. Diorite porphyry shows high Al[sub 2]O[sub 3], ZrO[sub 2], and REE abundances indicating that this rock is more fractionated. Basalts and andesites are plag-cpx-opx phyric. They often include glomeroporphyritic clots of cpx with amph coronas. Some rocks exhibit fluidal textures. Both volcanic and plutonic rocks show homogeneous geochemical features and similar crystallization sequences: Fe-Ti oxides---->plag---->opx + cpx----> brown zoned hbl, suggesting that they are cogenetic. Thus, the lower part of the Black Dyke Fm. likely represents the final products formed in a calc-alkaline magma chamber because pyroclastic rocks prevail over lava flows and abundant early crystal cumulates occur as plugs or as inclusions in the lavas and breccias.

  14. River Valley pluton, Ontario: A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

    USGS Publications Warehouse

    Ashwal, L.D.; Wooden, J.L.

    1989-01-01

    The River Valley pluton is a ca. 100 km2 body of anorthositic and gabbroic rocks located about 50 km northeast of Sudbury, Ontario. The pluton is situated entirely within the Grenville Province, but its western margin is a series of imbricate thrust faults associated with the Grenville Front Tectonic Zone. It is dominated by coarse leuconorite and leucogabbro, with lesser anorthosite, gabbro, and rare ultramafics. Igneous textured rocks are abundant and consist of plagioclase (An60-70) charged with Fe-Ti oxide inclusions, low Ca pyroxene (orthopyroxene and/or inverted pigeonite) and augite. The most unfractionated rocks are minor olivine gabbros with Fo70-80. A variety of deformed and recrystallized equivalents of the igneous-textured rocks is also present, and these are composed largely of calcic plagioclase and hornblende. Ten samples, including both igneous and deformed lithologies give a Pb-Pb whole-rock isochron of 2560??155Ma, which is our best estimate of the time of primary crystallization. The River Valley pluton is thus the oldest anorthositic intrusive yet reported from the Grenville Province, but is more calcic and augitic than typical massifs, and lacks their characteristic Fe-Ti oxide ore deposits. The River Valley body may be more akin to similar gabbro-anorthosite bodies situated at the boundary between the Archean Superior Province and Huronian supracrustal belt of the Southern Province west of the Grenville Front. An Sm-Nd isochron from 3 igneous-textured leucogabbros and an augite mineral separate gives 2377 ?? 68 Ma, implying slight disturbance of the Sm-Nd whole-rock-mineral system during later metamorphism. The Rb-Sr system has been substantially disturbed, giving an age of 2185 ?? 105 Ma, which is similar to internal Pb-Pb isochron ages of 2165 ?? 130 Ma and 2100 ?? 35 Ma for two igneous-textured rocks. It is uncertain whether these ages correspond to a discrete event at this time or represent a partial resetting of the Rb-Sr and Pb

  15. Contrasting petrogenesis of Mg-K and Fe-K granitoids and implications for post-collisional magmatism: case study from the late-Archaean Matok pluton (South Africa)

    NASA Astrophysics Data System (ADS)

    Laurent, Oscar; Rapopo, Mafusi; Stevens, Gary; Moyen, Jean-François; Martin, Hervé; Zeh, Armin; Doucelance, Régis

    2014-05-01

    Post-collisional, metaluminous high-K calc-alkaline granitoids emplaced throughout the last 3.0 Ga are compositionally diverse, ranging from Mg-rich (e.g. sanukitoids) to Fe-rich compositions, both being intimately associated locally. While the origin of Mg-K suites is fairly well understood, that of Fe-K magmas is much less constrained. In addition, no model accounts for the post-collisional nature of both granitoid types, in one hand, and their geochemical differences, on the other hand. This work addresses these issues investigating the petrography and geochemistry (major-, trace elements and Sm-Nd isotope data on whole rocks, trace element and in situ Sr-Hf-Nd isotopes on accessory phases) of the 2.69 Ga-old Matok pluton, emplaced in the northern Kaapvaal Craton (South Africa). It consists of diorites, granodiorites and monzogranites, which show clear petrographic and compositional affinities with other post-collisional Fe-K suites. In spite of unradionegic Hf-Nd isotope compositions (ɛNd(WR) = -2.7 to -4.6; ɛHf(Zrn) = -3.2 to -3.6) and radiogneic Sr ones (Sr(i) > 0.702), most of the Matok pluton derives from neither reworking of local continental crust, nor crustal contamination of basaltic melt. Whole-rock as well as accessory mineral geochemistry indicate that the whole suite fractionated from a common mafic parent, either by partial melting or crystallization. Geochemical modelling shows that this parent magma or source rock derives itself from the involvement of two distinct mantle sources: (1) enriched, subcontinental lithospheric mantle, which was metasomatized by sedimentary (or sediment-derived) material derived from local crust of the Pietersburg block; and (2) asthenospheric mantle. Mantle enrichment took place less than 0.3 Ga prior to the pluton emplacement, and explains the 'crustal' isotope signature of the Matok pluton. Involvement of both sources is the only relevant way to explain the differences between Fe-K suites, such as the Matok pluton

  16. Using Oxygen Isotopes of Zircon to Evaluate Magmatic Evolution and Crustal Contamination in the Halifax Pluton, Nova Scotia

    NASA Astrophysics Data System (ADS)

    Murray, K. E.; Lackey, J.; Valley, J. W.; Nowak, R.

    2007-12-01

    Oxygen isotope analysis of zircon (Zrc) is well suited for parsing out the magmatic history in granitoids. The Halifax pluton is the largest pluton (1060 km2) in the peraluminous South Mountain batholith. The Halifax pluton is mapped as a concentrically zoned body, with outer units comprising granodiorite, monzogranite and a mafic porphyry; these units are locally rich in metasedimentary xenoliths and magmatic enclaves. The exterior units surround a more felsic core of leucogranite [1]. Previous oxygen isotope studies of the pluton report high whole rock δ18O values that range from 10.7-11.7‰ [2], and indicate a significant supracrustal component in the source of the pluton. We report the first δ18O(Zrc) values from the Peggy's Cove monzogranite and an associated mafic porphyry. Samples were collected across 30 km of discontinuous exposures of the monzogranite. Values of δ18O(Zrc) vary from 7.71-8.26‰ (average = 8.15±±0.32‰(2 S.D.); n = 10). Small but systematic E-W regional variation in δ18O(Zrc) values suggests heterogeneous magmatic contamination within the monzogranite. Meter-scale magmatic enclaves, observed in close association with pods of diverse xenoliths and smaller enclaves at the western Cranberry Head locality, are slightly enriched in δ18O relative to the host monzogranite. These data combined support a model of magma mingling and heterogeneous mixing at the rim of the pluton, with contamination by high-δ18O rocks. Additional high-δ18O(Zrc) data from granodiorites on the northern margin of the Halifax pluton concur with these observations [3]. Typically, closed magmatic systems show increasing δ18O with SiO2 because more felsic magmas have a greater percentage of high-δ18O minerals such as quartz and feldspar. Thus, the Halifax pluton appears to exhibit an enrichment trend opposite of what would be expected of a closed evolving system. Emplacement mechanisms for the Halifax pluton proposed by previous workers suggest that the outer

  17. AMS significance of dykes and granite from a same pluton - An example from the French Massif Central

    NASA Astrophysics Data System (ADS)

    Talbot, J.-Y.; Chen, Y.; Faure, M.

    2003-04-01

    The relationships between plutons and dykes of granite have been the topic of many studies since the hypothesis of "dyke propagation" was proposed as the main mode of ascent and emplacement of granitic plutons. However, most of observed pluton-related dykes can not be interpreted as "feeder dykes" but are fed by the magma chamber. Nevertheless, few AMS studies were carried out in both a pluton and its associated dykes to evaluate their internal fabrics. In the Cévennes area (SE of the French Massif Central), the Aigoual -- Saint-Guiral -- Liron granitic pluton consists of two cogenetic granitic facies. The main body is a porphyritic granodiorite facies which is common in the plutons of the Cévennes area. In the northern part of the pluton, a dyke swarm develops in the continuation of the porphyritic facies. Those NE-SW-trending dykes are composed of microgranite with locally porphyritic texture. This pluton intrudes metamorphic units dated at ca. 340--330 Ma and related to a N-S-trending shortening event. The emplacement of the pluton dated at ca. 310 Ma occured during the late-orogenic extension of the Hercynian belt. This extension is characterized by an E-W to NW-SE-trending stretching. An AMS study was carried out on the two granitic facies of this pluton. As shown by surveys of magnetic mineralogy, such as thermomagnetism, hysteresis loops, bulk magnetic susceptibility measurements, microscopic observations, the paramagnetic minerals, that is biotite with amphibole in traces, are the main carriers of the AMS for the two facies. Microstructures indicate the lack of significant solid-state deformation in both facies suggesting that AMS fabric is of magmatic origin and that no deformation is recorded after the complete crystallisation of the magma. In the porphyritic facies, the AMS fabric pattern is characterized by an E-W to NW-SE-trending lineation with shallow or moderate plunges mainly eastward. In general, magnetic foliations dip moderately eastward. This

  18. Death Valley turtlebacks: Mesozoic contractional structures overprinted by Cenozoic extension and metamorphism beneath syn-extensional plutons

    NASA Astrophysics Data System (ADS)

    Pavlis, T. L.; Miller, M.; Serpa, L.

    2008-07-01

    The term turtleback was first coined to describe the curvilinear fault surfaces that produced a distinctive geomorphic form in the Black Mountains east of Death Valley, and although it was decades before their full significance was appreciated, they remain one of the most distinctive features of the extensional structure of the Death Valley region. Historically the interpretation of the features has varied markedly, and misconceptions about their character continue to abound, including descriptions in popular field guides for the area. It the 1990's, however, the full history of the systems began to be apparent from several key data: 1) the dating of the plutonic assemblage associated with the turtlebacks demonstrated that late Miocene, syn-extensional plutonism was fundamental to their formation; 2) the plutonic assemblage forms an intrusive sheet structurally above the turtlebacks, indicating a tie between much of the high grade metamorphism and Cenozoic plutonism; 3) a modern analog for the syn-extensional plutonism in the Black Mountains was recognized beneath Death Valley with the imaging of a mid-crustal magma body; 4) the Neogene structural history was worked out in the turtlebacks showing that folding of early-formed shear zones formed the turtleback anticlinoria but overprinting by brittle faults produced the final form as they cut obliquely across the older structure; and 5) the pre-extensional structural history was clarified, demonstrating that Mesozoic basement-involved thrust systems are present within the turtlebacks, but have been overprinted by the extensional system. An unresolved issue is the significance of Eocene U-Pb dates for pegmatites within the region, but presumably these relate somehow to the pre-extensional history. Miller and Pavlis (2005; E. Sci. Rev.) reviewed many features of the turtlebacks, and our working model for the region is that the turtlebacks originated as mid-crustal ductile-thrust systems within the Cordilleran fold

  19. Process for extracting technetium from alkaline solutions

    SciTech Connect

    Moyer, B.A.; Sachleben, R.A.; Bonnesen, P.V.

    1994-12-31

    This invention relates generally to a process for extracting technetium from nuclear wastes and more particularly to a process for extracting technetium from alkaline waste solutions containing technetium and high concentrations of alkali metal nitrates. A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate comprises the steps of: contacting the aqueous alkaline solution with a solvent consisting of a crown ether in a diluent, the diluent being a water-immiscible organic liquid in which the crown ether is soluble, for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution into the solvent; separating the solvent containing the technetium values from the aqueous alkaline solution; and stripping the technetium values from the solvent by contacting the solvent with water.

  20. Construction of an Upper Crustal Reservoir by Lateral Magma Propagation: New insights from Geochronological Data of La Gloria Pluton, Central Chile

    NASA Astrophysics Data System (ADS)

    Gutiérrez, F. J.; Guillong, M.; Payacán, I. J.; Aravena, A.; Bachmann, O.; Parada, M. A.

    2014-12-01

    La Gloria Pluton (LGP) is a 10 Ma shallow elongated NNW reservoir of 17 km length and 4-6 km width as part of a NS trend of Miocene plutons in Central Chile. New LA-ICPMS U-Pb ages in zircons of La Gloria Pluton indicate that crystallization occurs mostly within an interval between 11.2 to 10 Ma, with southeastward decreasing ages. Zircon crystallization ages are consistently older at the boundaries of the pluton than at the center for a given cross-section. At regional scale the ages of LGP follows a plutonic trend of southward decreasing age: Estero Yerba Loca (10 Ma) and San Francisco Batholith (SFB), in the north; and Cerro Mesón Alto (12.5 Ma) and San Gabriel (SG; 13 Ma), in the south. Both regional and local (within-LGP) age trends suggest: 1) a progressive northward migration of the main deep magmatic source during the Miocene; and 2) a southeastward lateral propagation of the magma during the reservoir construction. The lateral propagation of the magma is also supported by subhorizontal mineral and magnetic lineations with a preferred NNW orientation within LGP. The within-pluton age distribution and internal configuration suggest incremental construction with horizontal propagation of magma within channels. Because the lateral migration of the magma play an important role on the thermal structure of the cooling pluton we perform numerical simulations that account for reheating caused by refilling along the axial core of the pluton . We speculate that pre-existing shallow crustal structures (faults and folds) would allow lateral magma canalization, particularly between the lower highly deformed volcanic Abanico Fm. and the less deformed overlaying volcanic Farellones Fm. The pluton distribution and internal organization in and around LGP suggest incremental construction with vertical and horizontal migration of magma within channels and reservoirs, yielding plutonic complexes with protracted ages and elongated geometries.

  1. Minerals and melt inclusions as keys to understanding magma reservoir processes during formation of volcanic and plutonic mafic-ultramafic complexes in the Maimecha Kotui Province (Polar Siberia)

    NASA Astrophysics Data System (ADS)

    Simonov, Vladimir; Vasiliev, Yurii; Kotlyarov, Alexey; Stupakov, Sergey

    2016-04-01

    Magmatic complexes in the Maimecha Kotui Province (Polar Siberia) attract attention of researchers because they contain ultramafic volcanic rocks - meimechites, being products of crystallization of the ultrabasic deep mantle melts (Sobolev et al., 1991, 2009, 2011; Ryabchikov et al., 2002; Vasiliev, Gora, 2014). Effusive meimechites together with intrusive dunites of the Guli massif form ancient (253-246 Ma) volcanic and plutonic association, in which also pyroxenites and alkaline rocks are situated. Conditions of formation of this association were established with the help of minerals and melt inclusions study. The cumulative structure of the Guli massif dunites consists of rather large (2-4 mm) olivine crystals and dividing them zones (0.5-0.7 mm), filled with fine grains of clinopyroxenes and ore minerals (magnetite, ilmenite and chromite). The extended forms of well faceted pyroxene crystals testify to their fast growth from melt between cumulative olivines. Thus, crystallization of clinopyroxenes and ore minerals leads to formation between olivines ore pyroxenites, which are presented in the Guli massif by independent bodies. Analysis of olivine, Cr-spinel and clinopyroxene compositions testify to similarity of conditions of the Guli massif dunites crystallization on the one hand with formation of platinum-bearing Uralian-Alaskan-type mafic-ultramafic complexes and with another - show participation of meimechite magma. Major element composition of melt inclusions in Cr-spinel has shown that dunites of the Guli massif were crystallized with participation of subalkaline picrite magmatic systems, that are relative to melts, responsible of formation of platinum-bearing mafic-ultramafic complexes and meimechites. Peculiarities of trace and rare-earth elements distribution in melt inclusions in Cr-spinel of dunites are actually similar to inclusions in olivine of meimechites. Overall, data on composition of inclusions directly testify to formation of considered

  2. Alkaline-resistance model of subtilisin ALP I, a novel alkaline subtilisin.

    PubMed

    Maeda, H; Mizutani, O; Yamagata, Y; Ichishima, E; Nakajima, T

    2001-05-01

    The alkaline-resistance mechanism of the alkaline-stable enzymes is not yet known. To clarify the mechanism of alkaline-resistance of alkaline subtilisin, structural changes of two typical subtilisins, subtilisin ALP I (ALP I) and subtilisin Sendai (Sendai), were studied by means of physicochemical methods. Subtilisin NAT (NAT), which exhibits no alkaline resistance, was examined as a control. ALP I gradually lost its activity, accompanied by protein degradation, but, on the contrary, Sendai was stable under alkaline conditions. CD spectral measurements at neutral and alkaline pH indicated no apparent differences between ALP I and Sendai. A significant difference was observed on measurement of fluorescence emission spectra of the tryptophan residues of ALP I that were exposed on the enzyme surface. The fluorescence intensity of ALP I was greatly reduced under alkaline conditions; moreover, the reduction was reversed when alkaline-treated ALP I was neutralized. The fluorescence spectrum of Sendai remained unchanged. The enzymatic and optical activities of NAT were lost at high pH, indicating a lack of functional and structural stability in an alkaline environment. Judging from these results, the alkaline resistance is closely related to the surface structure of the enzyme molecule. PMID:11328588

  3. Tectonics of the Kola collision suture and adjacent Archaean and Early Proterozoic terrains in the northeastern region of the Baltic Shield

    NASA Astrophysics Data System (ADS)

    Berthelsen, Asger; Marker, Mogens

    1986-06-01

    As preparation for the deep-seismic and other geophysical experiments along the Polar Profile, which transects the Granulite belt and the Kola collision suture, structural field work has been performed in northernmost Finland and Norway, and published geological information including data from the neighbouring Soviet territory of the Kola Peninsula, have been compiled and reinterpreted. Based on these studies and a classification according to crustal and structural ages, the northeastern region of the Baltic Shield is divided into six major tectonic units. These units are separated and outlined by important low-angle, ductile shear or thrust zones of Late Archaean to Early Proterozoic age. The lateral extension of these units into Soviet territory and their involvement in large-scale crustal deformation structures, are described. Using the "view down the plunge" method, a generalised tectonic cross-section that predicts the crustal structures along the Polar Profile is compiled, and the structures around the Kola deep drill-hole are reinterpreted. The Kola suture belt, through parts of which the Kola deep bore-hole has been drilled, is considered to represent a ca. 1900 Ma old arc-continent and continent-continent collision suture. It divides the northeastern Shield region into two major crustal compartments: a Northern compartment (comprising the Murmansk and Sörvaranger units) and a Southern compartment (including the Inari unit, the Granulite belt and the Tanaelv belt, as well as the more southernly situated South Lapland-Karelia "craton" of the Karelian province of the Svecokarelian fold belt). The Kola suture belt is outlined by a 2-40 km wide and ca. 500 km long crustal belt composed of (1) Early Proterozoic (ca. 2400-2000 Ma old) metavolcanic and metasedimentary sequences which originally formed part of the attenuated margin of the Northern Archaean compartment, and (2) the remains of a ca. 2000-1900 Ma old, predominantly andesitic island-arc terrain. This

  4. Structural characterization and composition of Y-rich hainite from Sakharjok nepheline syenite pegmatite (Kola Peninsula, Russia)

    NASA Astrophysics Data System (ADS)

    Lyalina, L.; Zolotarev, A.; Selivanova, E.; Savchenko, Ye.; Zozulya, D.; Krivovichev, S.; Mikhailova, Yu.

    2015-08-01

    Y-rich hainite occurs in nepheline syenite pegmatite of the Sakharjok massif (Kola Peninsula, Russia). It forms euhedral prismatic crystals up to 2 mm in length as well as rims around an unidentified mineral phase (silicate of Ca, Y, Zr and Ti). The mineral is triclinic, space group P-1, a 9.6054(10), b 5.6928(6), c 7.3344(7) Å, α 89.903(2), β 101.082(2), γ 100.830(2)°, V 386.32(7) Å3, Z = 1. The calculated density is 3.39 g/cm3. Chemical composition of Sakharjok hainite is different from the previously published data by much higher Y and Nb contents up to 0.72 and 0.20 atoms per formula unit, respectively, by the two- to five-fold depletion in the LREEs and by the strong enrichment of the HREEs. From the single-crystal X-ray diffraction data, there is a significant amount of Y in the M1 site associated with the absence of Zr in it. Nb and Zr are concentrated in the M5 site substituting Ti. Combination of single-crystal X-ray diffraction data and electron microprobe data give the empirical formula (Ca1.04Y0.63REE0.24Mn0.02)∑1.93(Na0.92Ca0.77)∑1.69Ca2.00(Na0.65Ca0.10)∑0.75(Ti0.60Zr0.21Nb0.15Fe0.03)∑0.99((Si4.00Al0.02)∑4.02O14) (F2.61O1.39)∑4.00.

  5. Organochlorine pesticides, chlorinated dioxins and furans, and PCBs in peregrine falcon Falco peregrinus eggs from the Kola peninsula, Russia

    USGS Publications Warehouse

    Henny, C.J.; Ganusevich, S.A.; Ward, F.P.; Schwartz, T.R.

    1994-01-01

    Nesting of a bog-associated population of mlgfatory Peregrine Falcons, Falco peregrinus, along the Ponoy River depression, Kola Peninsula, Russia, has been studied since 1977. In 1987 91 production rates averaged 1.94 young per active nest and the number of breeding pairs increased from 4 to 10. In 1991, most eyrie sites were visited during the egg stage and a 'sample' egg was collected for contaminant analysis. Eight Peregrine Falcon eggs contained relatively low concentrations of p,p' -DOE (DOE) (geometric mean 3.5 g/g) and of other organochlorine pesticides. These DOE concentrations are similar to those reported in Peregrine Falcon eggs from an Alaskan population that had also showed a recent population increase. Eggshell thinning (11.4%) was similar to that found in Alaska. Concentrations of polychlorinated biphenyls (PCBs) were higher than DOE concentrations, comparable to the contamination profile shown by Peregrine Falcon populations in Fennoscandia, and were higher than those found in Alaskan birds. Before this study, no Peregrine Falcon eggs from Russia had 'been analyzed for PCB congeners, polychlorinated dibenzo- p-dioxins (PCDDs), or pol ychlorinated dibenzofurans (PCD Fs). Conversions of analytical concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), other PCDDs, PCDFs and PCB congeners based on relative aryl hydrocarbon hydroxylase induction potencies allowed the estimation of total 2,3,7,8- TCDD equivalents (TEQs). The TEQs are in the range that is associated with embryonic mortality in other species. Even though the Peregrine Falcon population now seems to be released from decades of a DOT problem, exposure to other contaminant continues. There is an obvious need to assess further the sources and longer-term trends of the PCBs. We also report residue concentrations from one White-tailed Eagle, Haliaeetus albicilla, egg.

  6. Long-term consequences for Northern Norway of a hypothetical release from the Kola nuclear power plant.

    PubMed

    Howard, B J; Wright, S M; Salbu, B; Skuterud, K L; Hove, K; Loe, R

    2004-07-01

    The spatial and temporal variation in radiocaesium and (90)Sr doses to two population groups of the two Northernmost counties of Norway, Troms and Finnmark, following a hypothetical accident at the Kola nuclear power plant (KNPP) have been estimated using a model implemented within a geographical information system. The hypothetical accident assumes a severe loss of coolant accident at the KNPP coincident with meteorological conditions causing significant radionuclide deposition in the two counties. External doses are estimated from ground deposition and the behaviour of the different population groups, and internal doses from predicted food product activity concentrations and dietary consumption data. Doses are predicted for reindeer keepers and other Norwegian inhabitants, taking account of existing (137)Cs and (90)Sr deposition but not including the remedial effect of any countermeasures that might be used. The predicted doses, arising mainly from radiocaesium, confirm the Arctic Monitoring and Assessment Programme assessment that residents of the Arctic are particularly vulnerable to radiocaesium contamination, which could persist for many years. External doses are predicted to be negligible compared to ingestion doses. Ingestion doses for reindeer keepers are predicted to exceed 1 mSv y(-1) for several decades primarily due to their high consumption of reindeer meat. Other Norwegians would also be potentially exposed to doses exceeding 1 mSv y(-1) for several years, especially if they consume many local products. Whilst reindeer production is the most important exposure pathway, freshwater fish, lamb meat, dairy products, mushrooms and berries are also significant contributors to predicted ingestion doses. Radionuclide fluxes, defined as the total output of radioactivity in food from an area for a unit time, are dominated by reindeer meat. The results show the need for an effective emergency response, with appropriate countermeasures, should an accident of the

  7. Natural radioactivity and radiation index of the major plutonic bodies in Greece.

    PubMed

    Papadopoulos, A; Christofides, G; Koroneos, A; Papadopoulou, L; Papastefanou, C; Stoulos, S

    2013-10-01

    The natural radioactivity of the major plutonic bodies in Greece, as well as the assessment of any potential health hazard due to their usage as decorative building materials is studied. One hundred and twenty one samples from every major plutonic body in Greece, including various rock-types from gabbro to granite, have been measured for their natural radioactivity using γ-spectrometry methodology. According to the experimental results, the natural radioactivity levels were ranged up to 315 Bq kg(-1) for (226)Ra, up to 376 Bq kg(-1) for (232)Th and up to 1632 Bq kg(-1) for (40)K, with arithmetic mean values and standard deviations of 74 (±51), 85 (±54) and 881 (±331) Bq kg(-1) respectively, which are below the international representative mean values for granite stones. The excess on the effective dose received annually indoors due to granite tiles usage is estimated considering a standard room model where granite tiles with 1.5 cm in thickness cover only the floor of the room. The increment on the external γ-radiation effective dose rate shows a Gaussian distribution well dispersed below 0.3 mSv y(-1), presenting a mean value of 0.14 (±0.06) mSv y(-1). In case of the internal α-radiation a log-normal distribution is appeared scattering below 0.5 mSv y(-1) with a mean value 0.19 (±0.13) mSv y(-1), for a well-ventilated living environment. In case of a poor-ventilated room the increment on internal effective dose rate is estimated with a mean value 0.27 (±0.19) mSv y(-1) scattering below 0.8 mSv y(-1). The majority of the samples increase the external as well as the internal dose less than 30% of the maximum permitted limit of the effective dose rate. Therefore, at least from radiological point of view, the plutonic rocks of Greece could be safely used as decorative building materials. PMID:23827232

  8. The 13 Ma Monts Ballons alkalic plutonic suite, Kerguelen Archipelago, Indian Ocean

    NASA Astrophysics Data System (ADS)

    Loftus, T.; Weis, D.; Scoates, J. S.; Giret, A.

    2011-12-01

    The 12.955 ± 0.011 Ma (U-Pb zircon) Monts Ballons plutonic suite comprises several small alkalic intrusions (0.3 km2) that were emplaced into older (~25 Ma) flood basalts in the central region of the Kerguelen Archipelago, a major oceanic island in the southern Indian Ocean related to magmatic activity associated with the long-lived (130 million years) Kerguelen mantle plume. The Monts Ballons intrusions contain a suite of rocks ranging from amphibole gabbros to nepheline syenites (silica-undersaturated suite) and are amongst the most alkalic rock types on the archipelago [1]. They represent the products of small degrees of melting of the Kerguelen mantle plume source. Samples from the Monts Ballons suite are enriched in highly incompatible trace elements with sub-parallel normalized trace element patterns. They define a small range of radiogenic isotopic ratios, and lie at the low end of Hf-Nd-Pb isotopic fields in comparison to the majority of volcanic and plutonic rocks on the archipelago, with average values at 13 Ma of ɛHf=-0.8±1.5, ɛNd=-1.2±07 and 206Pb/204Pb=18.2. Values of 87Sr/86Sr at 0.7052±2 fall within the range of the composition of the enriched Kerguelen plume as defined by basalts from the Courbet Peninsula [2]. The Monts Ballons compositions bridge a gap between the radiogenic compositions of the 25-24 Ma mildly alkalic flood basalts from Mt. Crozier and Baie Charrier and the less radiogenic lavas of the young (<10 Ma) alkalic rocks of the Upper Miocene Series and the recent Mt. Ross stratovolcano [3]. The Monts Ballons chemistry does not show any evidence for continental input to account for these enriched signatures typical of the Kerguelen plume. The magmas that crystallized to form the high-level Monts Ballons plutonic suite derive from the source of the enriched Kerguelen mantle plume and subsequently interacted and assimilated some of the underlying Cretaceous Kerguelen Plateau during ascent. [1] Scoates et al. (2006) Contrib. Min

  9. Oxygen Isotope Perspectives on Magma Sources and Pluton Assembly in Convergent Margin Batholiths

    NASA Astrophysics Data System (ADS)

    Lackey, J.

    2008-12-01

    Oxygen isotope (δ18O) analysis of zircon in the Sierra Nevada batholith (SNB) yields fresh insight on the origin of this and other convergent margin batholiths. Zircon precisely and accurately maps (δ18O) variation by circumventing the effects of differentiation and sub-solidus alteration[1]. New temporal and spatial δ18O patterns are recognized, and the findings have bearing in current debates on the tempo and mode of pluton and intrusive suite assembly [2-4]. At large scales, regional belts of high and low δ18O reveal markedly contrasting budgets of crust and mantle in magma sources at different points during formation of the batholith. Contrary to original thinking, recycling of supracrustal rocks is greater in the western than eastern SNB. Gradients of δ18O show variable input of crust and mantle within these regional belts; however, sharp shifts in δ18O between some belts suggest pre-batholith lithospheric breaks. Generally, δ18O breaks do not coincide with the 0.706 Sri line suggesting isotopic decoupling, either in sources or during crustal contamination. Where present, crustal contamination is limited to veneers on plutons, and is largely restricted to the western SNB. Careful investigation of individual intrusive suites, reveals details of source longevity. In the Tuolumne suite, limited variability of δ18O suggests remarkably source homogeneity despite evidence for protracted emplacement[2,4]. In contrast, the John Muir suite shows distinct trends in its older and younger plutons, with a δ18O transition recorded in the Lake Edison granodiorite. Thus, some suites may draw from stable sources over several million years, with differentiation in the upper crust creating zoning and textural diversity; others record source switching or depletion of sources. Over time, shifts in δ18O in the SNB are punctuated by major pulses of magmatism suggesting reorganization of sources, likely in response to intra-arc deformation[5]. Overall, results show that a

  10. Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

    NASA Astrophysics Data System (ADS)

    Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

    2016-02-01

    The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

  11. The relationship between adakitic, calc-alkaline volcanic rocks and TTGs: implications for the tectonic setting of the Karelian greenstone belts, Baltic Shield

    NASA Astrophysics Data System (ADS)

    Samsonov, A. V.; Bogina, M. M.; Bibikova, E. V.; Petrova, A. Yu.; Shchipansky, A. A.

    2005-01-01

    Two types of coeval acid-intermediate rocks with different petrological, geochemical and isotopic features have been discovered among volcanic rocks and surrounding synkinematic tonalite-trondhjemite-granodiorite (TTG) plutons of Late Archaean greenstone belts in the Karelian granite-greenstone terrane. Type-1 rocks comprise trondhjemites and sub-volcanic, occasionally volcanic dacite-rhyolite rocks. They are characterized by high Sr, low Y and HREE contents, high Sr/Y ratios, and strongly fractionated REE patterns with no significant positive or negative Eu anomaly. Initial ɛNd is positive, indicating a generation from juvenile source with little or no contribution of ancient continental crust. Type 2 is represented by diorite-granodiorites and calc-alkaline basalt-andesite-dacite-rhyolite (BADR) series. As compared to type 1, these rocks differ by their lower Sr, higher Y and HREE contents, lower Sr/Y ratios and less fractionated HREE patterns with negative Eu anomalies. Initial ɛNd varies from negative to positive values, thus indicating a variable contribution of sialic crust. Geochemistry of the two magmatic series suggests their formation in a convergent plate margin setting. The type-1 rocks resemble Phanerozoic adakites, which represent slab-derived melts contaminated by overlying mantle wedge. The type-2 rocks resemble BADR series, which were derived from a mantle wedge metasomatized by slab-derived fluids and melts, with subsequent variable crustal contamination. The spatial distribution of these two types of magmatic series defines the asymmetry of the studied granite-greenstone structures, which presumably reflects the primary lateral zoning of island arc formed under specific thermal conditions in the Archaean mantle. Adakite melts upraised to the surface in the frontal part of the island arc, where mantle wedge was thin, showing no or little interaction with metasomatized mantle, and formed adakite-type plutonic and sub-volcanic rocks. At greater

  12. U-Pb geochronology and geochemistry of Zahedan and Shah kuh plutons, eastern Iran: Implication for the late stage of the tectonic evolution of the South Sistan Zone

    NASA Astrophysics Data System (ADS)

    Mohammadi, Ali; Burg, Jean-Pierre; Ruh, Jonas; Von Quadt, Albrecht; Peytcheva, Irena

    2015-04-01

    The N-S trending Sistan Suture Zone (SSZ) in eastern Iran is attributed to eastward subduction beneath the Afghan continental block of an inlet of the Mesozoic Tethys Ocean. We present U-Pb zircon crystallization ages combined with petrography, major and trace element analyses, Hf isotopes, Rb-Sr and Sm-Nd isotopes of intermediate to granitic intrusions stretched along the southern segment of the SSZ. We obtained two clearly separated clusters of concordant ages, which are taken as the crystallization age of the host plutonic rocks. The first cluster, between ca 42.5 and ca 44.5 Ma from euhedral zircons of the main granodiorite to diorite and related dykes. The second age cluster span from ca 28.3 to ca 31 Ma. These ages were obtained for granites and dykes, the latter being consistently slightly younger than the country rock. The high SiO2 content (62-75 wt %) of Eocene magmatic rocks points to melts with a high crustal contribution in consistency with their relatively high-K (3-4.4 wt %) calc-alkaline nature. The high SiO2 and K contents in the Oligocene calk-alkaline rocks series shows adakite-like fractionation. Oligocene adakite-like rocks have relatively low to medium 87Sr/86Sr and 143Nd/144Nd ratios, which are similar to typical lower thick crust-derived adakites. The mix positive and negative ɛHf(T) values of all zircons from the 42.5-44.5 Ma shows mix nature of magma (the contamination of subduction related magma with partial melting of crust). The positive ɛHf(T) values of all zircons from the 28-31 Ma adakite-like rocks indicate that the magma was not produced from pure depleted mantle. Instead, they are consistent with a host magma source within a largely juvenile and subduction-related mafic lower crust. Eocene granitoids represent anatectic melts emplaced at higher crustal levels; in addition slab melts modified the mantle wedge and subsequent, contaminated mantle magmas fed intrusions such as the Zahedan diorite.

  13. Jurassic plutons in the Desolation wilderness, northern Sierra Nevada batholith, California: A new segment in the Jurassic magmatic arc

    SciTech Connect

    Sabine, C. . Quaternary Sciences Center)

    1993-04-01

    A 164[+-]7 Ma U-P zircon date establishes a Middle- to Late-Jurassic age for the Pyramid Peak granite and synplutonic dioritoids and hybrid rocks that comprise the Crystal Range suite, located southwest of Lake Tahoe. A Jurassic age is also assigned to the Keiths Dome quartz monzonite and the Desolation Valley and Camper Flat granodiorites (Loomis', 1983, Early Granitic Group) which are distinctly older than surrounding Cretaceous granitoids. The Keiths Dome quartz monzonite, the oldest pluton of the group, may be as old as 180 Ma and is distinguished by ductile shear zones and recrystallization textures which indicate an episode of deformation not undergone by other plutons. The Camper flat and Desolation Valley granodiorites are the youngest plutons of the group. ENE-trending microdiorite dikes filled extensional fractures, perpendicular to the direction of shortening, in all Jurassic plutons but on none of the Cretaceous bodies. Jurassic plutons may help constrain ages of metasedimentary and metavolcanic rocks and associated structures in the Mount Tallac roof pendant. The Pyramid Peak granite intrudes the Sailor Canyon Formation which bears Late Pliensbachian ammonites (Fisher, 1990), and the Keiths Dome quartz monzonite intrudes the overlying Tuttle Lake Formation and transects faults and shear zones in the pendant. Initial Sr isotope ratios for the Pyramid Peak granite range between 0.705427 and 0.706874, spanning the 0.706 value taken by some to mark the western limit of sialic lower crust. Data suggest an isotopically mixed source containing mantle and crustal components. Such an environment is not inconsistent with a passive continental margin where mafic magma invades rifted continental crust.

  14. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  15. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  16. Inorganic-organic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1978-01-01

    A flexible separator is reported for use between the electrodes of Ni-Cd and Ni-Zn batteries using alkaline electrolytes. The separator was made by coating a porous substrate with a battery separator composition. The coating material included a rubber-based resin copolymer, a plasticizer and inorganic and organic fillers which comprised 55% by volume or less of the coating as finally dried. One or more of the filler materials, whether organic or inorganic, is preferably active with the alkaline electrolyte to produce pores in the separator coating. The plasticizer was an organic material which is hydrolyzed by the alkaline electrolyte to improve conductivity of the separator coating.

  17. Process for extracting technetium from alkaline solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

    1995-01-01

    A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

  18. Exploring the plutonic crust at a fast-spreading ridge:new drilling at Hess Deep

    SciTech Connect

    Gillis, Kathryn M.; Snow, Jonathan E.; Klaus, Adam; Guerin, Gilles; Abe, Natsue; Akizawa, Norikatsu; Ceuleneer, Georges; Cheadle, Michael J.; Adriao, Alden de Brito; Faak, Kathrin; Falloon, Trevor J.; Friedman, Sarah A.; Godard, Marguerite M.; Harigane, Yumiko; Horst, Andrew J.; Hoshide, Takashi; Ildefonse, Benoit; Jean, Marlon M.; John, Barbara E.; Koepke, Juergen H.; Machi, Sumiaki; Maeda, Jinichiro; Marks, Naomi E.; McCaig, Andrew M.; Meyer, Romain; Morris, Antony; Nozaka, Toshio; Python, Marie; Saha, Abhishek; Wintsch, Robert P.

    2013-02-28

    Integrated Ocean Drilling Program (IODP) Hess Deep Expedition 345 was designed to sample lower crustal primitive gabbroic rocks that formed at the fast-spreading East Pacific Rise (EPR) in order to test models of magmatic accretion and the intensity of hydrothermal cooling at depth. The Hess Deep Rift was selected to exploit tectonic exposures of young EPR plutonic crust, building upon results from ODP Leg 147 as well as more recent submersible, remotely operated vehicle, and near-bottom surveys. The primary goal was to acquire the observations required to test end-member crustal accretion models that were in large part based on relationships from ophiolites, in combination with mid-ocean ridge geophysical studies. This goal was achieved with the recovery of primitive layered olivine gabbros and troctolites with many unexpected mineralogical and textural relationships, such as the abundance of orthopyroxene and the preservation of delicate skeletal olivine textures.

  19. The plutonic-volcanic connection: are we even on the right track? (Invited)

    NASA Astrophysics Data System (ADS)

    Lundstrom, C.; Chakraborty, P.; Zambardi, T.

    2013-12-01

    The connection between silicic volcanic and plutonic rocks is full of contradictions. Foremost, granitic plutons reflect long slow incremental emplacement yet vast amounts of aphyric ignimbrite can be erupted rapidly. Heat flow, geophysical tomography, geochronology, geochemistry and petrology all provide observations, yet we are far from any consensus. The two most popular suggestions for forming ignimbrites, extraction of partial melt from a granitic upper crust reservoir or lower crustal hot zone melting, are each inconsistent with some observations/constraints. 100% melting of a granite mush, which may be consistent with many observations, was previously proposed1 but dismissed due to the large amount of latent heat needed to completely melt a mush. This work first presents new non-traditional isotope ratio data (Fe, Si) for plutonic and volcanic rocks suites showing that like Harker diagrams, volcanics and plutonics produce identical systematic behavior with differentiation. δ56Fe forms upwardly curving trends with increasing silica whereas δ30Si increases linearly. The logical deduction is that volcanics reflect 100% mobilization of a granite mush (not necessarily melting). While the origin of NTSI variations remains debated, the systematic NTSI trends are consistent with prediction of a top-down thermal migration zone refining (TMZR) process2. In part 2, we assume TMZR generates a granitic mush and propose that an instability in this mush leads to a runaway effect that results in eruption of aphyric ignimbrite. Experiments show that wet andesite evolves to granite at the cold (400°C) end of a thermal gradient3 with hydrous peralkaline melt existing interstitially. Previous work4 shows that such melts show retrograde immiscibility, segregating into a water rich melt and a water poor melt with temperature increase. Thus, as the mush builds down into hot crust, it crosses the immiscibility boundary triggering release of the water-rich phase; buoyant rise and

  20. Magmatic construction and duration of solidification of Searchlight pluton, Eldorado Mountains, Nevada (USA)

    NASA Astrophysics Data System (ADS)

    Miller, J. S.; Cates, N. L.; Miller, C. F.; Wooden, J. L.; Means, M. A.; Ericksen, S.

    2003-12-01

    The process of chamber construction and the residence time of magma in mid- to upper crustal magma bodies have been illuminated by recent advances in high-resolution geochronology. Most work has so far concentrated on young volcanic systems; few geochrononlogic data have addressed magma chamber longevity and history from studying plutons. Plutons offer an important complementary record of magma processing and solidification, and can therefore reveal much about the internal workings of magma chambers. The Miocene Searchlight pluton (Nevada, USA) is a spectacular example of a very thick magma chamber (10-12 km). Crystal accumulation (mafic quartz monzonite cumulate), coupled with roof-down solidification (upper quartz monzonite) resulted in segregation of evolved felsic melt in the chamber interior (middle granite). Initially horizontal and gradational internal contacts and coplanar magmatic fabrics between all major units, geochemical mass balance, and very limited isotopic variation among major units, suggest that the entire pluton was molten at one time. However, the time inteval over which the chamber solidified was not well known. New TIMS and in situ ion microprobe U/Pb dating of zircon, combined with our earlier and ongoing field and isotopic studies, now appear to document a protracted magma chamber history. TIMS and ion microprobe dating (Stanford/USGS SHRIMP-RG) was done on two samples, and a third sample was dated by ion microprobe only. A multi-grain, multi-fraction discordia lower intercept age of 16.7+/-0.5 Ma (MSWD=22) was obtained by TIMS from the lower mafic quartz monzonite cumulate. Ion probe dating of zircons from the same sample yielded a 206Pb/238U age of 16.9+/-0.2 Ma (MSWD=1.3; N=24) in agreement with the TIMS lower intercept age. A discordia lower intercept age of 15.7+/-0.4 Ma (MSWD=3.7, one concordant point at 15.8 Ma) was obtained from the middle granite unit. Ion probe dating of zircons from the same sample yielded a 206Pb/238U age of 16

  1. Transport and Depositional Model for Large Country Rock Blocks Within the Searchlight Pluton, Southern Nevada

    NASA Astrophysics Data System (ADS)

    Perrault, D. S.; Furbish, D. J.; Miller, C. F.

    2006-05-01

    Searchlight pluton, a steeply tilted, 10 km thick Miocene intrusion in the Colorado River Extensional Corridor, exposes a zone with abundant, 5-400 m long blocks of Proterozoic gneiss. Blocks are present within a pair of subparallel horizons that make up a 2 km-thick zone and extend about 6 km laterally away from the pluton's north margin slightly oblique to the initially subhorizontal boundary between the pluton's middle unit (granite) and lower unit (qtz monzonite). Blocks are a variety of Precambrian metasedimentary gneisses, granitic gneisses, and mylonites. Blocks are commonly polylithologic and well foliated, with long and intermediate dimensions parallel to both their own foliation and that of the granitic host. Their average aspect ratio is ~ 4:1. Blocks within these horizons are interpreted as stoped (detached country rock that experience gravity- induced displacement) based on several lines of evidence. First, the distribution and abundances of blocks are not consistent with an isolated panel of wall rock (screen). The zone is laterally discontinuous (local abundances vary from ~ 0-40 %); transects a gradational (cm-m scale) internal contact at a slightly oblique angle; and tapers away from the pluton's margin. Second, while block foliations are homoclinal and show fairly consistent attitudes from block to block, block foliations are discordant with wall rock foliations at the same stratigraphic level (adjacent north wall). Third, mush disturbance features such as schlieren and enhanced feldspar foliation beneath blocks suggest a downward compaction. We interpret the blocks to have been emplaced after wall collapse events. We are using scaled settling experiments to clarify how blocks move within viscous fluids and interact with crystal mushes. The experiments, involving tabular ceramic blocks with density ρ = 1.75-2.20 g cm-3 settling in shampoo (ρ = 1.02 g cm-3) with viscosity μ = 20.35 Pa s, are scaled to order-of-magnitude by the particle Reynolds

  2. A topaz- and amazonite-bearing leucogranite pluton in eastern Xinjiang, NW China and its zoning

    NASA Astrophysics Data System (ADS)

    Gu, Lian-xing; Zhang, Zun-zhong; Wu, Chang-zhi; Gou, Xiao-qin; Liao, Jing-juan; Yang, Hao

    2011-10-01

    The highly evolved Baishitouquan (BST) beryl-mineralised and topaz-bearing amazonite granite pluton is situated in the eastern Tianshan orogen of northwestern China. This pluton exhibits five well-exposed lithological zones, which, gradational from the lowest level, are leucogranite (zone-a), amazonite-bearing granite (zone-b), amazonite granite (zone-c), topaz-bearing amazonite granite (zone-d) and topaz albite granite (zone-e). The rocks are composed mainly of quartz, albite, and K-feldspar with varying amounts of topaz and amazonite. Quartz and topaz phenocrysts are the earliest phases that crystallised from the melt. Amazonite which replaced albite and K-feldspar was formed at the late magmatic stage or during the magmatic-hydrothermal transition. Geochemically, this pluton is characterised by high F (>2 wt.%) and Rb (499.5-1087.04 ppm), low P 2O 5 (⩽0.06 wt.%), Na 2O > K 2O, A/NKC = 1.00-1.11, low ratios of K/Rb, Al/Ga, Y/Ho, Zr/Ha and Nb/Ta, Σ14 REE = 28.6-231.9 ppm with gull wing-shaped distribution patterns (La CN/Lu CN = 0.11-0.68, Eu/Eu * = 0.0005-0.0110) and tetrad effects, and δ 18O = 9.75-7.32‰. Melt and fluid-melt inclusions coexist with liquid and vapour inclusions. The rocks were originated from a highly evolved granitic magma. The BST pluton exhibits transition in the following aspects from zone-a to zone-e: (1) As quartz and topaz phenocrysts progressively increase in size and crystal euhedral shape, rock textures change from equigranular to porphyritic. (2) Amazonite begins to appear in zone-b and becomes most concentrated in zone-c, whereas topaz begins to appear in zone-d becoming highly concentrated in zone-e. (3) Li and (Al + Ti) increase in white mica. (4) Petrochemically, there are general trends of increasing F, Al 2O 3 and Na 2O, and decreasing SiO 2, (Fe 2O 3 + FeO + MgO + MnO) and K 2O. Plots of normative compositions on the Qz-Ab-Or diagram move gradually towards the Ab apex. (5) Overall, Cr, Ni, Co, V, W, Nb, Zr, U, Th and Y

  3. Neo-tectonic fracturing after emplacement of quaternary granitic pluton in the Kakkonda geothermal field, Japan

    SciTech Connect

    Doi, N.; Kato, O.; Kanisawa, S.; Ishikawa, K.

    1995-12-31

    The fracture which occurs in the Kakkonda geothermal system was formed by neo-tectonic stress after the emplacement of the neo-granite (Quaternary Kakkonda Granite) at middle Pleistocene to recent. The characteristic contrast in permeability at ca.1.5 km is strongly controlled by the contact metamorphic zone, especially cordierite and higher grade metamorphic zones, in which the high temperature (320{degrees}C<) and low permeable deep reservoir was created. The five geothermal wells 2.5-3.0 km deep have clarified that a microearthquake zone below -1.0 km shows high permeability especially at the margin of the Kakkonda Granite, and low permeability outside of a microearthquake zone. The Kakkonda Granite is a composite pluton which has very few fractures inside of it. Thus, neo-tectonic fracturing has developed in the non-metamorphosed Tertiary formations and the margin of the Kakkonda Granite.

  4. Numerical simulations of late-stage magma flow in La Gloria pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Gutierrez, F. J.; Payacan, I.; Bachmann, O.; Parada, M.

    2012-12-01

    To better understand the internal dynamics of small, shallow, silicic magma reservoirs, we performed 2-D time-dependent fluid dynamical numerical simulations of a cooling magma encased in the upper crust. This model takes into account the main magmatic phases (crystals, melt, and exsolved H2O), whose stability fields were calibrated by the MELTS thermodynamic software. The results of those simulations were compared to the composition, mineralogy, and AMS data obtained for La Gloria Pluton (LGP), a 10 Ma old intrusion with c. 2.5 km of vertical exposure located in the southern Andes. LGP represents a particularly simple case of a shallow silicic magma reservoir of about 250 km3. LGP was assembled in a few pulses and cooled over a short time interval where subsolidus reequilibration was not pervasive, allowing identification of early and late magmatic conditions. LGP is vertically zoned from granodiorite/quartz monzodiorite to quartz monzonite towards the roof. Hornblende, bitotite, and minor magnetite are ubiquitous mafic phases. AMS samples were collected at 46 sites to determine the magnetic anisotropy susceptibility tensor. The magnetic fabric has an oblate shape. Lineations are weak and have a N-NW trend with a nearly horizontal dip. Foliations are more pronounced, having NW trends and dips that vary gradually from vertical at the walls to horizontal at the center and near the roof of the chamber. After 2 to 6 k.y. of simulated evolution, the resulting convection pattern in the crystallizing reservoir is consistent with the magnetic fabric, largely produced in the shear zone between the convecting liquid-dominated core and the growing solidification fronts adjacent to the walls. The bulk of the reservoir remains fairly homogeneous through time due to convection stirring. Magnetic lineations represent axisymmetric convection parallel to the main pluton elongation direction, whereas magnetic foliations represent shear localization near the magma locking point

  5. Intermetallic compounds, copper and palladium alloys in Au-Pd ore of the Skaergaard pluton, Greenland

    NASA Astrophysics Data System (ADS)

    Rudashevsky, N. S.; Rudashevsky, V. N.; Nielsen, T. F. D.

    2015-12-01

    Copper-palladium intermetallic compounds and alloys (2314 grains) from the Au-Pd ore of the Skaergaard layered gabbroic pluton have been studied. Skaergaardite PdCu, nielsenite PdCu3, (Cu,Pd)β, (Cu,Pd)α, (Pd,Cu,Au,Pt) alloys, and native palladium have been identified as a result of 1680 microprobe analyses. The average compositions and various chemical varieties of these minerals are characterized, as well as vertical and lateral zoning in distribution of noble metals. The primary Pd-Cu alloys were formed within a wide temperature interval broadly synchronously with cooling and crystallization of host gabbro and in close association with separation of Fe-Cu sulfide liquid. In the course of crystallization of residual gabbroic melt enriched in iron, noble and heavy metals and saturated with the supercritical aqueous fluid, PGE and Au are selectively concentrated in the Fe-Cu sulfide phase as Pd-Cu and Cu-Au alloys.

  6. Geology and geochemistry of the Mount Riley-Mount Cox pluton, Dona Ana County, New Mexico

    SciTech Connect

    Zimbelman, D.R.; Siems, D.F.; Kilburn, J.E.; Hubert, A.E.

    1985-01-01

    The Mount Riley-Mount Cox area is comprised of a relatively homogeneous pluton of rhyodacite rising some 1600 feet above the La Mesa surface. The pluton, of apparent Tertiary age, intrudes Cretaceous sedimentary rocks and Tertiary ( ) latite and tuff. The rhyodacite is holocrystalline, light gray to pinkish gray, porphyritic to microporphyritic, and locally banded. Phenocrysts include hornblende, quartz, biotite, and calcite. The phenocrysts range in size from 0.2 to 2 mm and make up one to fifteen percent of the rock. The phenocrysts often display a glomerophyric texture within a trachytic groundmass. The groundmass ranges from cryptocrystalline to very fine grained and is composed of plagioclase, quartz, potassium feldspar, hornblende/biotite, and iron-oxide material. Locally, the rhyodacite displays millimeter-scale banding and a poikilitic texture consisting of quartz oikiocrysts and plagioclase chadocrysts. The rhyodacite averages 68.74%, SiO/sub 2/, 0.39% TiO/sub 2/, 16.40% Al/sub 2/O/sub 3/, 2.87% Fe/sub t/, 0.10% MnO, 1.21% MgO, 2.56% CaO, 3.79% Na/sub 2/O, and 3.96% K/sub 2/O. The rhyodacite is cut by veins and veinlets of brown to white calcite. The veins attain a maximum thickness of one meter, are locally bordered by calcite-cemented breccia zones, and locally include pyrite. The veins trend north or northwest, consistent with regional trends for the Rio Grande rift and the Texas Lineament, respectively. Sixty-five samples of rhyodacite, breccia, and vein were analyzed for 31 elements by emission-spectrographic methods. Trace-element data suggestive of hydrothermal mineralization was not recognized.

  7. Petrology and geochemistry of the Russian peak pluton, Klamath Mountains, northern California

    SciTech Connect

    Cotkin, S.J.

    1987-01-01

    The Jurassic Russian Peak pluton consists of an older peridotite-to-quartz diorite complex intruded by younger granodiorite. U-Pb ages of 159 Ma have been obtained for both units. The peridotite-to-quartz diorite complex consists principally of quartz diorite; however, cumulate ultramafic rocks occur where it is in contact with Ordovician serpentinite, and the following zonation from serpentinite to quartz diorite is present: peridotite, pyroxenite, hornblendite, eucrite, and diorite. In order to evaluate the petrogenesis of the pluton a combination of field, petrographic, microprobe, X-ray fluorescence, and instrumental neutron activation analysis, and Rb-Sr data have been collected. Major and trace element modeling indicates that quartz-rich quartz diorite formed by crystallization, quartz-poor quartz diorite by accumulation of crystals plus trapped liquid, and ultramafic rocks by assimilation of serpentinite. Granodiorite on the other hand can be modeled by crystallization alone, with the precipitation of plagioclase, amphibole, and biotite accounting for the major and minor element variations. REE modeling indicates that a garnet-clinopyroxene amphibolite is a plausible source. A variety of techniques have been used to decipher the conditions of crystallization in each unit, including a comparison of paragenesis with crystallization experiments, geological thermometry and barometry, and phase equilibria. Pressure of intrusion is considered to have been approximately 3 kbar. The peridotite-to-quartz diorite complex intruded at about 1000/sup 0/C and was completely crystalline at 790/sup 0/C. Granodiorite intruded at somewhat lower temperatures and was completely crystalline at about 700/sup 0/C. The oxygen fugacity for both units was slightly above QFM. At its solidus, granodiorite was saturated with H/sub 2/O, which may account for the pervasive deuteric alteration of this unit.

  8. Europium mass balance in polymict samples and implications for plutonic rocks of the lunar crust

    SciTech Connect

    Korotev, R.L.; Haskin, L.A. )

    1988-07-01

    From correlations of SM concentration and Sm/Eu ratio with Th concentration for a large number of polymict samples from various locations in the lunar highlands and the value of 0.91 {mu}g/g for the mean Th concentration of the highlands surface crust obtained by the orbiting gamma-ray experiments. The authors estimate the mean concentrations of Sm and Eu in the lunar surface crust to be between 2 and 3 {mu}g/g Sm and 0.7 and 1.2 {mu}g/g Eu. The compositional trends indicate that there is no significant enrichment or depletion of Eu, on the average, compared to Sm relative to chondritic abundances, i.e., there is no significant Eu anomaly in average upper crust. Although rich in plagioclase ({approximately}70%), the upper crust does not offer evidence for a gross vertical separation of plagioclase from the final liquid from which it crystallized. This and the chondritic ratio of Eu/Al in average highlands material imply that the net effect of the processes that led to formation of the lunar crust was to put most of the Al and incompatible elements in the crust. Among plutonic rocks, only plagioclase in rocks from the magnesian suite can supply the excess Eu in the polymict rocks. Owing to the intermediate value of the mean Mg/Fe ratio of the crust, a significant fraction of the mafic rocks of the lunar highlands must have lower Mg/Fe ratios than the norites and troctolites of the magnesian-suite of plutonic rocks. A large fraction of the plagioclase in the lunar crust is associated not with ferroan anorthosite, but with more mafic rocks. There is little evidence in the Eu data that the lunar crust ever consisted of a thick shell of nearly pure plagioclase, as envisioned in some formulations of the magma ocean model of its formation.

  9. Structural evolution of the Rieserferner Pluton: insight into the localization of deformation and regional tectonics implications

    NASA Astrophysics Data System (ADS)

    Ceccato, Alberto; Pennacchioni, Giorgio

    2016-04-01

    The Rieserferner pluton (RFP, Eastern Alps, 32.2±0.4 Ma, Romer et al. 2003) represents a relatively deep intrusion (12-15 km; Cesare, 1994) among Periadriatic plutons. The central portion of the RFP consists of dominant tonalites and granodiorites that show a sequence of solid-state deformation structures developed during pluton cooling and exhumation. This sequence includes: (1) quartz veins, filling two set of steeply-dipping joints trending respectively E-W and NW-SE, commonly showing a millimetric grain size and associated with strike-slip displacement. (2) Quartz- and locally epidote-filled shallowly E-dipping joint set, commonly exploited as discrete derived from both the quartz veins and the host tonalite. These mylonites show a composite sense of shear with a first stage of left-lateral strike-slip followed by a top-to-E dip-slip (normal) movement. The synmylonitic assemblage includes biotite + plagioclase + white mica + epidote ± sphene ± garnet. (3) Set of N-S-trending steeply-dipping joints. These joints are concentrated in zones 1-2 m wide, separated by otherwise un-jointed domains a few tens to hundred meters wide, and are commonly exploited as brittle-ductile faults with dominant dip-slip (normal) kinematics. The mineral assemblage of fault rocks includes white mica + calcite ± chlorite ± quartz. The joints/faults are locally involved in folding. (4) Mafic dikes, dated at 26.3±3 Ma (Steenken et al., 2000), locally injecting the N-S trending set of joints. (5) Cataclasite- and pseudotachylyte-bearing faults also forming a set of steeply-dipping N-S-trending structures. These faults are commonly associated with epidote veins surrounded by bleaching haloes. (6) Zeolite-bearing faults marked by whitish cataclasites, fault gouges and mirror-like surfaces. These faults have a complex oblique- to strike-slip kinematics with an overall N-S trending lineation. As observed in other plutons (e.g. Adamello; Pennacchioni et al., 2006), the network of

  10. Composite seal reduces alkaline battery leakage

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Plitt, K. F.

    1965-01-01

    Composite seal consisting of rubber or plastic washers and a metal washer reduces alkaline battery leakage. Adhesive is applied to each washer interface, and the washers are held together mechanically.

  11. Batievaite-(Y), Y2Ca2Ti[Si2O7]2(OH)2(H2O)4, a new mineral from nepheline syenite pegmatite in the Sakharjok massif, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Lyalina, L. M.; Zolotarev, A. A.; Selivanova, E. A.; Savchenko, Ye. E.; Krivovichev, S. V.; Mikhailova, Yu. A.; Kadyrova, G. I.; Zozulya, D. R.

    2016-05-01

    Batievaite-(Y), Y2Ca2Ti[Si2O7]2(OH)2(H2O)4, is a new mineral found in nepheline syenite pegmatite in the Sakharjok alkaline massif, Western Keivy, Kola Peninsula, Russia. The pegmatite mainly consists of nepheline, albite, alkali pyroxenes, amphiboles, biotite and zeolites. Batievaite-(Y) is a late-pegmatitic or hydrothermal mineral associated with meliphanite, fluorite, calcite, zircon, britholite-group minerals, leucophanite, gadolinite-subgroup minerals, titanite, smectites, pyrochlore-group minerals, zirkelite, cerianite-(Ce), rutile, behoite, ilmenite, apatite-group minerals, mimetite, molybdenite, and nickeline. Batievaite-(Y) is pale-cream coloured with white streak and dull, greasy or pearly luster. Its Mohs hardness is 5-5.5. No cleavage or parting was observed. The measured density is 3.45(5) g/cm3. Batievaite-(Y) is optically biaxial positive, α 1.745(5), β 1.747(5), γ 1.752(5) (λ 589 nm), 2V meas. = 60(5)°, 2V calc. = 65°. Batievaite-(Y) is triclinic, space group P-1, a 9.4024(8), b 5.5623(5), c 7.3784(6) Å, α 89.919(2), β 101.408(2), γ 96.621(2)°, V 375.65(6) Å3 and Z = 1. The eight strongest lines of the X-ray powder diffraction pattern [d(Å)(I)(hkl)] are: 2.991(100)(11-2), 7.238(36)(00-1), 3.061(30)(300), 4.350(23)(0-1-1), 9.145(17)(100), 4.042(16)(11-1), 2.819(16)(3-10), 3.745(13)(2-10). The chemical composition determined by electron probe microanalysis (EPMA) is (wt.%): Nb2O5 2.25, TiO2 8.01, ZrO2 2.72, SiO2 29.96, Al2O3 0.56, Fe2O3 0.43, Y2O3 11.45, La2O3 0.22, Ce2O3 0.33, Nd2O3 0.02, Gd2O3 0.07, Dy2O3 0.47, Er2O3 1.07, Tm2O3 0.25, Yb2O3 2.81, Lu2O3 0.45, CaO 24.98, MnO 1.31, MgO 0.01, Na2O 1.13, K2O 0.02, F 2.88, Cl 0.19, H2O 6.75 (determined on the basis of crystal structure data), O = (F,Cl) -1.25, total 97.09 wt.%. The empirical formula based on the EPMA and single-crystal structure analyses is (Y0.81Ca0.65Mn0.15Zr0.12Yb0.11Er0.04Fe3+ 0.04Ce0.02Dy0.02Lu0.02La0.01Tm0.01)Σ2.00((H2O)0.75Ca0.70□0.55)Σ2.00Ca2.00(□0.61Na0.25( H2O

  12. Technetium recovery from high alkaline solution

    DOEpatents

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  13. Alkaline tolerant dextranase from streptomyces anulatus

    DOEpatents

    Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  14. Evaluation of the alkaline electrolysis of zinc

    SciTech Connect

    Meisenhelder, J.H.; Brown, A.P.; Loutfy, R.O.; Yao, N.P.

    1981-05-01

    The alkaline leach and electrolysis process for zinc production is compared to the conventional acid-sulfate process in terms of both energy saving and technical merit. In addition, the potential for industrial application of the alkaline process is discussed on the basis of present market conditions, possible future zinc market scenarios, and the probability of increased secondary zinc recovery. In primary zinc production, the energy-saving potential for the alkaline process was estimated to be greater than 10%, even when significantly larger electrolysis current densities than those required for the sulfate process are used. The principal technical advantages of the alkaline process are that it can handle low-grade, high-iron-content or oxidized ores (like most of those found in the US) in a more cost- and energy-efficient manner than can the sulfate process. Additionally, in the electrowinning operation, the alkaline process should be technically superior because a dendritic or sponge deposit is formed that is amenable to automated collection without interruption of the electrolysis. Also, use of the higher current densities would result in significant capital cost reductions. Alkaline-based electrolytic recovery processes were considered for the recycling of zinc from smelter baghouse dusts and from the potential source of nickel/zinc electric-vehicle batteries. In all comparisons, an alkaline process was shown to be technically superior and, particularly for the baghouse dusts, energetically and economically superior to alternatively proposed recovery methods based on sulfate electrolysis. It is concluded that the alkaline zinc method is an important alternative technology to the conventional acid zinc process. (WHK)

  15. Geochemical and Isotopic Data for Oligocene Ignimbrites, Calderas, and Granitic Plutons, Southern Stillwater Range and Clan Alpine Mountains: Insights into the Volcanic-Plutonic Connection and Crustal Evolution in Western Nevada

    NASA Astrophysics Data System (ADS)

    John, D. A.; Colgan, J. P.; Watts, K. E.; Henry, C.; Cousens, B.

    2015-12-01

    Oligocene calderas and underlying plutons in the southern Stillwater Range (SSR) and Clan Alpine Mountains (CAM) in western Nevada were tilted (40->90°) by large-magnitude Miocene extension and unconformably overlain by 15-13 Ma intermediate and mafic lava flows. New geologic mapping, geochemistry, and Ar-Ar and U-Pb dating document 2 brief periods of magmatism resulting in 5 nested calderas and related plutons in sections locally ≥9 km thick. Early magmatism at ~29 Ma included the Deep Canyon caldera in CAM, and in the SSR, pre-caldera rhyolites, ~5 km of pre- and post-collapse intermediate lavas and rhyolite tuff that filled Job Canyon caldera (JC, ~29.4 to 28.8 Ma), and the >4-5 km thick IXL pluton (~28.5 Ma) that intruded JC and is compositionally similar to the tuff and lava flows. The second period included 3 ignimbrite units in 3 calderas: small-volume tuff of Louderback Mountains (LM, low-silica rhyolite; ≥600 m thick; ~25.3 Ma); multiple cooling units of tuff of Poco Canyon (PC, high-silica rhyolite; ≤4.5 km thick; ~25.3 Ma); and ≥2500 km3 of tuff of Elevenmile Canyon (EC, trachydacite to rhyolite; ≤4.5 km thick; 25.1 Ma) that covers ~1600 km2 and extends east from SSR to the northern Desatoya Mountains. The composite Freeman Creek pluton (granodiorite, ~25.0 Ma; granite, ~24.8 Ma) and Chalk Mountain rhyolite porphyry (~25.2 Ma) and granite (~24.8 Ma) plutons intruded LM, PC and EC calderas. Radiogenic isotopes in all caldera units are similar (Sri~0.7050, ΕNd~0.0), while oxygen isotope compositions are variable (δ18Oquartz=5.7-8.4‰, δ18Ozircon=4.1-6.3‰), corresponding to a magmatic range of 5.6-7.6‰, including <6‰ values for JC and lower PC rhyolites. U-Pb zircon dating shows homogeneous age populations and few/no xenocrysts or antecrysts. These data show that (1) thick plutons (>2-5 km) underlie compositionally and temporally related caldera-filling ignimbrites, (2) caldera-forming cycles are isotopically variable, requiring

  16. A 2 Million Year History of Plutonism and Volcanism in the Searchlight Magma System, Eldorado Mountains, Nevada (USA)

    NASA Astrophysics Data System (ADS)

    Miller, J.; Miller, C.; Wooden, J.; Perrault, D.; Hodge, K.; Faulds, J.; Cates, N.; Means, M.

    2006-12-01

    Subvolcanic plutons provide an important record of magma processing and solidification of upper crustal magma bodies but rarely can they be compared with volcanic output from the same magma system. In the Colorado River extensional corridor of southern Nevada, steep tilting caused by crustal extension has exposed outstanding examples of large intrusions that have complementary volcanic output. One of the best examples is the 12 km thick Searchlight pluton and its overlying volcanic cover. Earlier work in the pluton documented vertical growth, wherein crystal accumulation (mafic quartz monzonite cumulate) and roof-down solidification (upper quartz monzonite) resulted in segregation of evolved felsic melt in the chamber interior (middle granite). This general evolutionary sequence is mirrored by lava flow stratigraphy in steeply tilted volcanic sections that are structurally above the roof of Searchlight pluton. We have obtained more than 400 ion microprobe U/Pb zircon ages (Stanford/USGS SHRIMP-RG) on more than 20 samples for the pluton and overlying volcanic rocks in order to temporally link the volcanic rocks with the intrusive rocks. The oldest unit from Searchlight pluton is a gabbro pod near the northern margin of the lower Searchlight quartz monzonite that yielded a 206Pb/238U age of 17.7±0.3 Ma (all age errors reported are 1σ; MSWD ~1 or lower except where noted) but the main lower quartz monzonite from structurally deep has a 206Pb/238U age of 16.9±0.2 Ma. This age is the same age as trachydacite porphyry dikes and pods (16.6±0.3 Ma) that intrude upper Searchlight (but not lower Searchlight) and an identical trachydacite lava flow from near the base of a sequence of trachydacite flows above the pluton (16.9±0.4 Ma; MSWD 1.9). Samples of the middle granite and a gabbro that interacts with the granite are interpreted to be the last materials to solidify in the pluton and have 206Pb/238U ages ranging from 15.9-16.2 Ma but with MSWD's >3. Distinct age peaks

  17. Alkaline Water and Longevity: A Murine Study

    PubMed Central

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models. PMID:27340414

  18. Performed surfactant-optimized aqueous alkaline flood

    SciTech Connect

    Thigpen, D.R.; Lawson, J.B.; Nelson, R.C.

    1991-11-26

    This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

  19. Carboniferous magmatism in the Evora Massif (southwest Portugal, Ossa-Morena Zone): from typical arc calc-alkaline to adakitic-like magmatism

    NASA Astrophysics Data System (ADS)

    Lima, Selma M.; Neiva, Ana M. R.; Ramos, Joao M. F.

    2014-05-01

    The Evora Massif is one of the subdivisions of western Ossa-Morena Zone. It is a dome-like structure mainly composed of Ediacaran, Cambrian and Ordovician country rocks, affected by medium- and high-grade metamorphism coeval with the emplacement of several mafic to felsic intrusive bodies. The last magmatic event recorded in this area (Carboniferous) consists of calc-alkaline volcanism and voluminous plutonism (mainly composed by tonalites, gabbros, diorites and late-orogenic granodiorites and granites) [1]. Detailed chemical and isotopic studies from Evora Massif plutons were performed in the last few years. Whole-rock chemical and isotopic data suggest that the Hospitais tonalite (HT), Alto de Sao Bento area (ASB) and Reguengos de Monsaraz pluton (RM) resulted from fractional crystallization of mantle-derived magmas followed by mixing with variable proportions of crustal melts [2-4]. U-Pb ID-TIMS data indicate an age of 337-335 for the RM [4]. The Pavia pluton is a multiphase granitic body constructed incrementally by the episodic emplacement of several batches of magma (at 328 Ma, ca. 324 Ma and 319-317 Ma) [5]. The main granitic phases range from tonalite to two-mica granite that contain rare surmicaceous and fine-grained enclaves, and granitic and amphibolitic xenoliths. On the other hand, they are cut by abundant rhyodacite porphyries, microgranites (s.l.) and pegmatite dikes, predominantly oriented NE-SW and NW-SE. Although each phase seems to represent a distinct batch of magma, whole-rock Sr-Nd isotopic data suggest a similar and fairly homogenous source for all the constituent phases. Initial 87Sr/86Sr varies between 0.70428 and 0.7058 and ɛ Ndt ranges from -3.4 to +0.4, pointing towards a mantle or juvenile crust origin. A higher variation is observed in whole-rock δ18O (5.6-9.6 o), consistent with assimilation of crust. The PP was interpreted as the result of assimilation-fractional crystallization of a basaltic magma. Substantial differences between

  20. Soil organic carbon sequestration as affected by afforestation: the Darab Kola forest (north of Iran) case study.

    PubMed

    Kooch, Yahya; Hosseini, Seyed Mohsen; Zaccone, Claudio; Jalilvand, Hamid; Hojjati, Seyed Mohammad

    2012-09-01

    Following the ratification of the Kyoto Protocol, afforestation of formerly arable lands and/or degraded areas has been acknowledged as a land-use change contributing to the mitigation of increasing atmospheric CO(2) concentration in the atmosphere. In the present work, we study the soil organic carbon sequestration (SOCS) in 21 year old stands of maple (Acer velutinum Bioss.), oak (Quercus castaneifolia C.A. Mey.), and red pine (Pinus brutia Ten.) in the Darab Kola region, north of Iran. Soil samples were collected at four different depths (0-10, 10-20, 20-30, and 30-40 cm), and characterized with respect to bulk density, water content, electrical conductivity, pH, texture, lime content, total organic C, total N, and earthworm density and biomass. Data showed that afforested stands significantly affected soil characteristics, also raising SOCS phenomena, with values of 163.3, 120.6, and 102.1 Mg C ha(-1) for red pine, oak and maple stands, respectively, vs. 83.0 Mg C ha(-1) for the control region. Even if the dynamics of organic matter (OM) in soil is very complex and affected by several pedo-climatic factors, a stepwise regression method indicates that SOCS values in the studied area could be predicted using the following parameters, i.e., sand, clay, lime, and total N contents, and C/N ratio. In particular, although the chemical and physical stabilization capacity of organic C by soil is believed to be mainly governed by clay content, regression analysis showed a positive correlation between SOCS and sand (R = 0.86(**)), whereas a negative correlation with clay (R = -0.77(**)) was observed, thus suggesting that most of this organic C occurs as particulate OM instead of mineral-associated OM. Although the proposed models do not take into account possible changes due to natural and anthropogenic processes, they represent a simple way that could be used to evaluate and/or monitor the potential of each forest plantation in immobilizing organic C in soil (thus

  1. Palaeomagnetic constraints from granodioritic plutons (Jiaodong Peninsula): New insights on Late Mesozoic continental extension in Eastern Asia

    NASA Astrophysics Data System (ADS)

    Charles, Nicolas; Chen, Yan; Augier, Romain; Gumiaux, Charles; Lin, Wei; Faure, Michel; Monié, Patrick; Choulet, Flavien; Wu, Fuyuan; Zhu, Rixiang; Wang, Qingchen

    2011-08-01

    Mechanism and kinematics of the Late Mesozoic continental extension event of Eastern Asia are still debated. In order to better constrain its evolution, two granodioritic plutons of the Jiaodong Peninsula have been chosen as targets for a time-constrained palaeomagnetic study. Indeed, plutons are devoid of visible deformation, did not experience rotation along horizontal axis and are precisely dated by U/Pb and 40Ar/ 39Ar methods. Multidomain (MD) magnetite has been identified as the principal magnetic remanent carrier. The interpolation of existing and new U/Pb and 40Ar/ 39Ar ages revealed that characteristic remanent magnetisation was acquired in a narrow range of 116 ± 2 Ma. Twenty out of 27 sites present stable magnetic directions calculated from high-temperature or high-coercive components. The observations of the solo normal magnetic polarity for this palaeomagnetic collection and of the magnetic remanent age consistent with the Cretaceous Normal Superchron (CNS) argue that the characteristic magnetic remanence may be considered as primary. Detailed field observations of the intrusive relationship between the plutons and country rocks and Anisotropy of Magnetic Susceptibility (AMS) study reveal the absence of the subsequent deformation of plutons, or rigid rotation of plutons along a horizontal axis. Two palaeomagnetic poles have been therefore calculated from these plutons. Among 12 out 15 Cretaceous palaeomagnetic poles, including the two new poles provided by this study, from the Jiaodong Peninsula and on both sides of Tan-Lu and Muping-Jimo faults are statistically consistent. As a result, the Jiaodong Peninsula behaved as a rigid block as internal deformation appears negligible. The remaining three derived poles are probably due to the secular variation or/and the vicinity of fault zones near of the palaeomagnetic sampling site. Thus, they can not be applied to the peninsula-scaled tectonics. Comparison of these time-constrained Cretaceous

  2. The role of felsic microgranular enclaves on the evolution of some Neoproterozoic granite plutons in SE Brazil

    NASA Astrophysics Data System (ADS)

    Alves, Adriana; Janasi, Valdecir A.; Pereira, Giovanna

    2010-05-01

    Recent studies of granite petrogenesis are strongly influenced by the finding that mafic microgranular enclaves (mme) witness frequent and volumetrically significant contribution of mantle-derived magmas to the origin and evolution of granitic melts, be it as a heat source and/or as a source compositional diversity. On the other hand, the origin of felsic microgranular enclaves (fme) is still a matter of debate; current hypotheses consider them as fragments of chilled margins, products of protracted hybridization between invading basic magmas and resident granite mushes or products of interaction between fairly similar melts. Felsic microgranular enclaves are widespread in various granite plutons from SE Brazil, in many cases surpassing mme in size and volume. Two groups of occurrences are studied in more detail illustrate different scenarios, with and without clear connections with mafic magmas. In the Mauá and Mogi das Cruzes plutons, made up of (muscovite)-biotite monzogranite, only fme occur, and the participation of more mafic melts is not evident from field structures or from whole rock and mineral chemical/isotope data. Our preferred model relate the fme to self-mixing events, suggesting mingling/mixing between highly viscous and chemically similar felsic endmembers. In the Itu Batholith, mme enclaves occur, albeit in very different volumes, in three chemically distinct plutons, all with A-type chemical affinities, In the rapakivi Salto Pluton, fme are large (dm to meter-sized) and widespread, except in a central body of porphyry granite. Scattered cm-sized mme of variable composition, some clearly brought as inclusions in the fme, are thought to represent different stages of hybridization, as indicated by disequilibrum features common also in the host syenogranites (rapakivi texture; mafic-rimmed quartz). The enclave assemblage of the Cabreúva Pluton is similarly dominated by fme, but larger mme and small diorite occurrences are evidence that basic magmas

  3. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Leukocyte alkaline phosphatase test. 864.7660... Leukocyte alkaline phosphatase test. (a) Identification. A leukocyte alkaline phosphatase test is a device used to identify the enzyme leukocyte alkaline phosphatase in neutrophilic granulocytes...

  4. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leukocyte alkaline phosphatase test. 864.7660... Leukocyte alkaline phosphatase test. (a) Identification. A leukocyte alkaline phosphatase test is a device used to identify the enzyme leukocyte alkaline phosphatase in neutrophilic granulocytes...

  5. Late Ediacaran (605-580 Ma) post-collisional alkaline magmatism in the Arabian-Nubian Shield: A case study of Serbal ring-shaped intrusion, southern Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Azer, Mokhles K.

    2013-11-01

    The Serbal pluton is a late Neoproterozoic (605-580 Ma) post-collisional A-type granites in southern Sinai, Egypt (northernmost Arabian-Nubian Shield, ANS). It is characterized by discontinuous ring-shaped outcrops dislocated by later faulting. The pluton intrudes late Neoproterozoic metamorphic and high-K calc-alkaline rocks. The Serbal pluton mostly comprises an outer zone of alkali feldspar granite surrounding a core of peralkaline granite. Gradational and sharp contacts in the Serbal granites suggest that they were emplaced with a very short time interval, still before complete crystallization of the earlier batch. Serbal granites are highly evolved (75.98-78.52 wt.% SiO2) and display the typical geochemical characteristics of post-collisional A-type granites, namely high SiO2, Na2O + K2O, FeO*/MgO, Ga/Al, Zr, Nb, Ga and Y and low CaO, MgO, Ba, and Sr. They are rich in REE and have extreme Eu-negative anomalies (Eu/Eu* = 0.01-0.23). The chemical characteristics indicate that the peralkaline granite shares many features of granites with the tetrad REE effect. The Serbal pluton evolved through fractional crystallization of a parental magma derived through partial melting of a juvenile crustal protolith that had been extracted from a source having mantle geochemical and isotopic characteristics. The crystallization temperatures using Fe-Ti oxides of the Serbal granites point to their formation at high temperatures, up to 650-850 °C at a shallow depth of emplacement (<10 km).

  6. Cambrian-Ordovician (500 Ma) alkalic plutonism in southwestern New Mexico: U-Th-Pb isotopic data from the Florida Mountains

    USGS Publications Warehouse

    Evans, K.V.; Clemons, R.E.

    1988-01-01

    A major alkalic igneous suite in the Florida Mountains of southwestern New Mexico has been dated by the U-Th-Pb method on zircon as latest Cambrian to earliest Ordovician. The results firmly document the presence of lower Paleozoic alkalic plutons in southwestern New Mexico. Implications of these data include: 1) a diamictite that nonconformably overlies the plutonic complex is not Late Proterozoic as suggested by previous workers on the basis of correlation with similar deposits in the Cordillera; 2) the Bliss Sandstone, thought to be Late Cambrian in the Florida Mountains area, is clearly in depositional contact with the alkalic plutonic complex and must be younger than 503??10 Ma; and 3) the alkalic plutonism, a type commonly associated with extensional tectonics, may have considerable significance in deciphering the poorly understood early Paleozoic tectonics in this region. -from Authors

  7. Composition of coarse-grained magnetite from pegmatite dikes related to plutons of quartz monzonite in the Jabal Lababa area, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Overstreet, William C.; Mousa, Hassan; Matzko, John J.

    1985-01-01

    Crystals of magnetite as large as 30 mm long and 7 mm thick are locally present in quartz-rich zones of interior and exterior pegmatite dikes related to plutons of quartz monzonite in the Jabal Lababa area. Niobium, tin, and yttrium are strongly enriched in six specimens of magnetite from interior pegmatite dikes in a small pluton where these elements form geochemical anomalies in nonmagnetic heavy-mineral concentrates from wadi sediment. Less abundant anomalous elements in the magnetite are molybdenum, lead, and zirconium, which also tend to be present in anomalous amounts in the nonmagnetic concentrates from the niobium-bearing pluton. The most anomalous trace element in the magnetite is zinc, which is at least 10 times as abundant as it is in the quartz monzonite plutons or in the nonmagnetic concentrates. The capacity of magnetite to scavenge molybdenum, zinc, niobium, lead, tin, yttrium, and zirconium suggests the possible utility of magnetite as a geochemical sample medium.

  8. A paleomagnetic and stable isotope study of the pluton at Rio Hondo near Questa, New Mexico: implications for CRM related to hydrothermal alteration

    USGS Publications Warehouse

    Hagstrum, J.T.; Johnson, C.M.

    1986-01-01

    Paleomagnetic and rock magnetic data combined with stable isotope data from the middle Tertiary pluton along the Rio Hondo in northern New Mexico suggest that its magnetic remanence has both thermal (TRM) and high-temperature chemical (CRM) components. Oxygen isotope temperatures indicate that magnetite associated with the more rapidly cooled higher levels of the pluton, and with mafic inclusions and cogenetic rhyolitic dikes sampled at lower levels of exposure, ceased subsolidus recrystallization and isotopic exchange above its Curie temperature (580??C) in the presence of a magmatic fluid. Continued cooling imparted a TRM to these portions of the pluton. The more slowly cooled granodiorite at lower levels has quartz-magnetite isotopic temperatures that are below the Curie temperature of magnetite implying that its magnetization is high-temperature CRM. Sub-Curie isotopic temperatures for other granitic plutons in the western U.S.A. suggest that CRM may be commonly derived from subsolidus interactions between magnetite and magmatic fluids in plutonic rocks. A meteoric-hydrothermal system generated by the cooling Rio Hondo pluton, and not by younger adjacent intrusions, resulted in limited alteration along zones of high permeability near the southern margin of the Rio Hondo pluton, and in more prevasive alteration of the pluton to the north. The meteoric-hydrothermal alteration occurred at relatively high temperatures (> 350??C) and, with the exception of local chloritization, caused little visible alteration of the rocks. The isotopic ratios indicate that little of the magnetite could have grown from or exchanged with a meteoric-hydrothermal fluid. ?? 1986.

  9. Forceful emplacement of the Eureka Valley-Joshua Flat-Beer Creek composite pluton into a structural basin in eastern California; internal structure and wall rock deformation

    NASA Astrophysics Data System (ADS)

    Morgan, Sven; Law, Richard; de Saint Blanquat, Michel

    2013-11-01

    Anisotropy of Magnetic Susceptibility parameters have been analyzed at 311 locations in the Eureka Valley-Joshua Flat-Beer Creek (EJB) pluton of eastern California. The large amount of data has allowed for the AMS parameters to be contoured using techniques that both reveal map-scale trends and emphasize small-scale differences. The contour maps suggest that magnetic susceptibility is dominantly controlled by composition of the magma but may also be affected by emplacement-related strain as the magma chamber inflated and forced the wall rocks outward. Pluton construction involved two major pulses of different composition magmas that were emplaced sequentially but with overlapping periods of crystallization. The magmas initially intruded as sill-like bodies into a structural basin. The magnetic foliation of the pluton cuts across internal magmatic contacts on the map scale and is parallel to local contacts between the pluton and surrounding metasedimentary wall rocks. The magnetic fabric is similar in orientation and symmetry to intense flattening strains recorded in the aureole rocks. The metasedimentary wall rocks have been shortened between 60 and 70% and this strain magnitude is approximately equal on the west, south, and east margins of the pluton. Strain in the wall rocks is dominantly flattening and concentrated into a narrow (1 km wide) inner aureole. Mapping of bedding/cleavage intersection lineations south of the pluton indicates that the magma made room for itself by translating the wall rocks outward and rotating the already inward dipping wall rocks of the structural basin to sub-vertical. Stretching of the inner aureole around an expanding magma chamber was responsible for the intense shortening. Limited data on the Marble Canyon pluton to the south of the EJB pluton indicates a very similar emplacement process.

  10. Kolaviron, Biflavonoid Complex from the Seed of Garcinia kola Attenuated Angiotensin II- and Lypopolysaccharide-induced Vascular Smooth Muscle Cell Proliferation and Nitric Oxide Production

    PubMed Central

    Oyagbemi, Ademola Adetokunbo; Omobowale, Temidayo Olutayo; Adedapo, Adeolu Alex; Yakubu, Momoh Audu

    2016-01-01

    Introduction: Kolaviron (KV), a biflavonoid extract from Garcinia kola seeds has been reported to possess anti-inflammatory, anti-oxidant, hepato-protective, cardio-protective, nephro-protective and other arrays of chemopreventive capabilities but the mechanism of action is still not completely understood. Materials and Methods: In this study, we investigated the anti-proliferative, anti-inflammatory and anti-oxidative potential of KV in cultured Vascular Smooth Muscle Cells (VSMCs). Effects of KV (25-100 μg/mL) on VSMC proliferation alone or following treatments with mitogen and proinflammatory agents Angiotensin II (Ag II, 10-6 M) and lipopolysaccharide (LPS, 100 μg/mL) and effects on NO production were determined. Cellular proliferations were determined by MTT assay, nitric oxide (NO) level was determined by Griess assay. KV dose-and time dependently attenuated VSMC growth. Results: Treatment of VSMCs with Ag II and LPS significantly enhanced proliferation of the cell which was significantly attenuated by the treatment with KV. Treatment of VSMC with LPS significantly increased nitric oxide (NO) level in the media which was attenuated by KV. These results demonstrated anti-proliferative anti-inflammatory properties of KV as it clearly inhibited cellular proliferation induced by mitogens as well as LPS-induced inflammatory processes. Conclusion: Therefore, KV may mitigate cardiovascular conditions that involve cell proliferation, free radical generation and inflammatory processes such as hypertension, diabetes and stroke. However, the molecular mechanism of action of KV needs to be investigated. SUMMARY Angiotensin-induced cell proliferationKolaviron mitigates angiotensin-induced cell proliferationKolaviron ameliorates nitric oxide productionKolaviron offers antioxidant activity. Abbreviations Used: VSMCs: Vascular Smooth Muscle Cells, Ag II: Angiotensin II, KV: Kolaviron, LPS: lypopolysaccharide, NO: Nitric Oxide, DMEM: Dulbecco's modified Eagle's medium, MTT

  11. Chemistry and petrology of the Apennine Front, Apollo 15. I - KREEP basalts and plutonic rocks. II - Impact melt rocks

    NASA Technical Reports Server (NTRS)

    Simon, S. B.; Papike, J. J.; Laul, J. C.

    1988-01-01

    The mineralogy, petrology, and chemistry of rock fragments for the Apennine Front coarse fines (10-4 and 4-2 mm) have been determined. The data are consistent with a single eruptive event that produced several flows. It is found that most of the plutonic rocks are ferroan in nature, with a few belonging to the Mg-suite. The mineral and bulk chemistry of KREEP basalts and the composition of ferroan anorthosites are discussed. Petrographic studies of 21 impact melts are also presented, showing a variety of textures. It is found that the Apollo 15 impact melts are mixtures of low-K Fra Mauro, KREEP, and plutonic components. The Ni/Ir ratios of the melt rocks are shown to be greater than chondritic values, indicating ancient and/or iron meteorite components.

  12. Mineralogy and geochemistry of the Late Neoproterozoic rare metal granitoids of Gabal El-Ineigi pluton, Northern Arabian-Nubian Shield, Egypt

    NASA Astrophysics Data System (ADS)

    Sami, Mabrouk; Ntaflos, Theodoros; Mohamed, Haroun A.; Farahat, Esam S.; Ahmed, Awaad F.

    2016-04-01

    Gabal El-Ineigi granitoid pluton is situated in the Central Eastern Desert of Egypt and is considered as one of the good examples of the fluorite bearing rare metal granites in the Arabian Nubian Shield (ANS). It constitutes a multiphase pluton consists of porphyritic syenogranites (SG) and coarse to medium grained highly evolved alkali-feldspar granites (AFG) intruded into the older granodiorites and metagabbro-diorite rocks. Petrographic features indicate that quartz, K-feldspar (perthite, Or97‑99), plagioclase (albite, An0‑6) and biotite are the major mineral phases of both granitic types with subordinate muscovite that is observed only in the AFG. Columbite, rutile, fluorite, zircon and thorite are the significant accessory minerals in the AFG while, allanite is exclusively encountered in the SG. Mineral chemistry study reveals that Nb-Ta-Ti-bearing oxides [columbite-group minerals (CGM)] and Nb-bearing oxides (ilmenorutile) represent the most common Nb-Ta host in the AFG. The CGM are represented mostly by complex zoned columbite-(Fe) and rarely by yttrocolumbite-(Y), with Mn/(Mn+Fe) ratios ranging from 0.17 to 0.31. Xenomorphic fluorite (F=46-51 wt%) is commonly filling the spaces between the major mineral phases and sometimes host rare metal minerals, e.g. columbite and thorite. Euhedral zoned allanite (Ce-Nd) is the common REE bearing mineral encountered in the SG. Geochemically, Gabal El-Ineigi granitoids are metaluminous (A/CNK= 0.95-0.99) related to post-collosional A2-type granites. The late phase AFG have distinctive geochemical features typical of rare-metal granites. They are highly fractionated calc-alkaline granitoids characterized by high Rb, Nb, Y, U and many HFSE contents, and extremely low Sr and Ba contents (4-35 and 13-18 ppm, respectively). Moreover, their REE patterns show pronounced negative Eu anomalies (Eu/Eu*=0.03 - 0.05) and tetrad effect (TE1,3=1.16 and 1.42), implying extensive fractionation via fluid-rock interaction that

  13. Temporal Evolution of Volcanic and Plutonic Magmas Related to Porphyry Copper Ores Based on Zircon Geochemistry

    NASA Astrophysics Data System (ADS)

    Dilles, J. H.; Lee, R. G.; Wooden, J. L.; Koleszar, A. M.

    2015-12-01

    Porphyry Cu (Mo-Au) and epithermal Au-Ag ores are globally associated with shallow hydrous, strongly oxidized, and sulfur-rich arc intrusions. In many localities, long-lived magmatism includes evolution from early andesitic volcanic (v) and plutonic (p) rocks to later dacitic or rhyolitic compositions dominated by plutons. We compare zircon compositions from three igneous suites with different time spans: Yerington, USA (1 m.y., p>v), El Salvador, Chile (4 m.y., p>v), and Yanacocha, Peru (6 m.y., v>p). At Yerington granite dikes and ores formed in one event, at ES in 2 to 3 events spanning 3 m.y., and at Yanacocha in 6 events spanning 5 m.y. At both ES and Yanacocha, high-Al amphiboles likely crystallized at high temperature in the mid-crust and attest to deep magmas that periodically recharged the shallow chambers. At Yanacocha, these amphiboles contain anhydrite inclusions that require magmas were sulfur-rich and strongly oxidized (~NNO+2). The Ti-in-zircon geothermometer provides estimates of 920º to 620º C for zircon crystallization, and records both core to rim cooling and locally high temperature rim overgrowths. Ore-related silicic porphyries yield near-solidus crystallization temperatures of 750-650°C consistent with low zircon saturation temperatures. The latter zircons have large positive Ce/Ce* and small negative Eu/Eu*≥0.4 anomalies attesting to strongly oxidized conditions (Ballard et al., 2001), which we propose result from crystallization and SO2 loss to the magmatic-hydrothermal ore fluid (Dilles et al., 2015). The Hf, REE, Y, U, and Th contents of zircons are diverse in the magma suites, and Th/U vs Yb/Gd plots suggest a dominant role of crystal fractionation with lesser roles for both crustal contamination and mixing with high temperature deep-sourced mafic magma. Ce/Sm vs Yb/Gd plots suggest that magma REE contents at <900°C are dominated by early crystallization of hornblende and apatite, and late crystallization (~<780°C) of titanite

  14. Spatial distribution analysis of igneous textures: Numerical modeling and interpretation of crystal accumulation in plutons

    NASA Astrophysics Data System (ADS)

    Špillar, Václav; Dolejš, David

    2014-05-01

    systematic and progressive decrease in melt extraction towards the pluton roof. The melt extraction has appeared at initial phenocryst crystallinities of ~10 %. By contrast, olivine crystal patterns in the cumulate zone of komatiite flows record degree of melt extraction up to over 80 % (crystal accumulation by a factor of three). The modeling is consistent with the phenocrysts in porphyritic rocks being early crystals, possibly displaced from their original site, rather than the late-stage products coarsened during the period of subsolidus annealing. Our results provide an approach and constraining parameters to quantitatively assess the mechanical mobility and the role of crystal accumulation during the magma emplacement and pluton construction based on textural record.

  15. Fractionation of Zr and Hf during the differentiation of peralkaline magmatic system (Lovozero rare metal deposit, Kola Peninsula)

    NASA Astrophysics Data System (ADS)

    Kogarko, Liya

    2016-04-01

    Zirconium and hafnium are valuable strategic metals. We assessed principal features of the distribution of these elements in peralkaline rocks, ores and rock-forming and accessory minerals of Lovozero complex. The accumulation of these elements during the evolution of alkaline magma of Lovozero deposit up to extremely high concentrations in eudialyte ores (5-8% ZrO2 and 1200-1800 ppm Hf) has been established. These ores represent valuable complex raw material not only for Zr and Hf, but for REE as well. We evaluated partition coefficients of these elements in alkaline pyroxenes (aegirines) from porphyry-like agpaitic lujavrites of Lovozero massif which are 0.40 for zirconium and 0.58 for hafnium. We assessed variations of Zr/Hf ratio for all the rocks of Lovozero alkaline massif. The growth of this ratio in the course of the evolution of alkaline magma has been observed from 38 in the earliest magmatic phase, to 44 in the second phase and to 51-53 in the latest manifestation of alkaline magmatsm. On the basis of the obtained data and equations of equilibrium and fractional crystallization the model of the fractionation of zirconium and hafnium during the evolution of Lovozero intrusion has been constructed. We have demonstrated that the source of strongly enriched magmatic systems similar to Lovozero rare metal deposit is short-lived enriched reservoir - metasomatized and carbonatized mantle substrate. We investigated the fractionation of zirconium and hafnium in carbonatized mantle xenoliths from East Antarctica. The elevated Zr/Hf ratios (up to 125) in metasomatized xenoliths by comparison with the chondritic value have been found. The main reactions of carbonate metasomatism lead to the replacement of primary orthopyroxene by clinopyroxene 2Mg2Si2O6 + CaMg(CO3)2 = 2Mg2SiO4 + CaMgSi2O6 + 2CO2 3CaMg(CO3)2 + CaMgSi2O6 = 4CaCO3 + 2Mg2SiO4 + 2CO2 The substantial expansion of the clinopyroxene crystallization field results in increase of Zr/Hf ratio in equilibrium

  16. High temperature fracturing and ductile deformation during cooling of a pluton: The Lake Edison granodiorite (Sierra Nevada batholith, California)

    NASA Astrophysics Data System (ADS)

    Pennacchioni, Giorgio; Zucchi, Eleonora

    2013-05-01

    In the Bear Creek area of the Sierra Nevada batholith, California, the high temperature postmagmatic deformation structures of the Lake Edison granodiorite include steeply-dipping orthogneiss foliations, joints, and ductile shear zones that nucleated on joints and leucocratic dykes. Exploitation of segmented joints resulted in sharply bounded, thin shear zones and in large slip gradients near the shear zone tips causing the deformation of the host rock at contractional domains. The orthogneiss foliation intensifies towards the contact with the younger Mono Creek granite and locally defines the dextral Rosy Finch Shear Zone (RFSZ), a major kilometre-wide zone crosscutting the pluton contacts. Joints predominantly strike at N70-90°E over most of the Lake Edison pluton and are exploited as sinistral shear zones, both within and outside the RFSZ. In a narrow (˜250 m thick) zone at the contact with the younger Mono Creek granite, within the RFSZ, the Lake Edison granodiorite includes different sets of dextral and sinistral shear zones/joints (the latter corresponding to the set that dominates over the rest of the Lake Edison pluton). These shear zones/joints potentially fit with a composite Y-R-R' shear fracture pattern associated with the RFSZ, or with a pattern consisting of Y-R-shear fractures and rotated T' mode I extensional fractures. The mineral assemblage of shear zones, and the microstructure and texture of quartz mylonites indicate that ductile deformation occurred above 500 °C. Joints and ductile shearing alternated and developed coevally. The existing kinematic models do not fully capture the structural complexity of the area or the spatial distribution of the deformation and magmatic structures. Future models should account more completely for the character of ductile and brittle deformation as these plutons were emplaced and cooled.

  17. Jim River and Hodzana plutons, Alaska: the role of assimilation in the petrogenesis of syenite and granite

    SciTech Connect

    Blum, J.D.; Blum, A.E.; Dillon, J.T.

    1985-01-01

    Early Cretaceous plutonic rocks in central Alaska intrude both Devonian to Jurassic oceanic rocks of the Angayuchum terrane (AT) and early Paleozoic to Precambrian continental metasediments of the Ruby terrane (RT). Most plutons intrude only the RT and are biotite and two-mice granite. The Hodzana pluton intrudes both fault-bounded terranes, constraining movement between them to the emplacement age of about 110 million years, and is mainly biotite-amphibole granite with some monzodiorite. Modal and chemical data from the Jim River and Hodzana plutons define two distinct compositional trends. One trend is monzonitic to syenitic while the other is mostly granitic. The two suites are the same age, yet cannot be related by simple differentiation due to a pronounced chemical discontinuity. Rb-Sr whole-rock isochrons yield an age of 112 million years and (87Sr/86Sr)o of .7078 for the syenitic suite, and an age of 108 million years and (87Sr/86Sr)o of .7079 for the granitic suite. The authors suggest that the monzonite represents a primary magma that formed in the lower crust or mantle and initiated upper crustal melting as it intruded the AT and RT. Assimilation of continental crust could have allowed the portion of the magma that intruded the RT to evolve from a monzonite to a granite. Fractionation of these two parent magmas may have resulted in the contemporaneous syenitic and granitic suites. The two suites may reflect the contrasting composition of assimilated wallrock across the AT-RT boundary. Isotopic studies of the wallrocks are in progress and may help to constrain the amount and composition of crust that was assimilated where the magma intruded the AT versus the RT.

  18. Map showing distribution and classification of felsic plutonic rocks in the eastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Du Bray, E.A.

    1983-01-01

    This 1:500,000-scale compilation shows the distribution of felsic plutonic rocks, lithologic types, and associated mineralization in an area between lat 21° and 24°30’ N., long 43°30’ and 46° E. It is part of a shieldwide compilation being done within the framework of Saudi Arabian Deputy Ministry for Mineral Resources projects 2.04 and 3.12.

  19. Regional geochemical study of the felsic plutonic rocks in the Nuqrah Quadrangle, sheet 25E, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Hall, W.E.; Dellinger, David; Selner, G.I.

    1985-01-01

    Pan-concentration samples collected from wadis draining the north end of Jabal Safad contain anomalous Sn, Mo, Pb, and La. Four samples contain 250 to 1,000 ppm of tin. The tin anomaly is associated with a small aplitic pluton intrusive into the Jabal Safad alkalic granite complex. A brief reconnaissance of the area did not reveal any greisen or cassiterite mineralization. However, further exploration work in the area is recommended.

  20. Zircon Geochemical and Isotopic Constraints on the Evolution of the Mount Givens Pluton, Central Sierra Nevada Batholith

    NASA Astrophysics Data System (ADS)

    Sendek, C.; Lackey, J. S.; Miller, J. S.; Davies, G. R.; Valley, J. W.; Kitajima, K.

    2015-12-01

    The Late Cretaceous Mt. Givens pluton (central Sierra Nevada batholith, CA) is noteworthy for its large size (≈1400 km2) and relative compositional and textural homogeneity. It has been proposed as a plutonic analog for "monotonous intermediate" ignimbrites. The pluton is characterized by a 30 km wide ellipse shaped northern lobe that connects with a long mass about 15 km wide and extending 50 km SE. The northern lobe was constructed over 7 m.y. (from 98 to 91 Ma) with progressively younger ages toward the interior. This inward younging is accompanied by transitions to more felsic compositions and from equigranular to K-spar porphyritic textures. The large elongated mass extending to the SE (ca. 95-91 Ma) is more homogeneous, mostly equigranular granodiorite with subordinate K-spar-phyric granodiorite. Small diorite intrusions (10's to 100's m2) are also present and locally mingle and hybridize with the host granodiorite. Unlike other Late Cretaceous zoned intrusions (the Sierra Crest intrusions), the equigranular, and K-spar porphyritic phases of the Givens have similar trace element characteristics. All zircons have high Ti-in-zircon model temperatures (850-1000 °C), pronounced negative Eu anomalies, and curved MREE and HREE patterns. These characteristics indicate that zircon grew early and that initial magmas were likely undersaturated in zircon. Significant within sample variations in δ18O (up to 1.5‰) and eHf (up to 8 units) require mixing of isotopically distinct magmas in the Givens magma system after they had begun crystallizing zircon, but well before solidification. O and Hf isotopic variation within the granodiorites shows distinct geographic variation, with higher δ18O and more negative eHf values along the western margin of the pluton. This trend is consistent with earlier work suggesting that the Givens intruded across the Panthalassan-North American lithospheric boundary.

  1. The Ajo Mining District, Pima County, Arizona--Evidence for Middle Cenozoic Detachment Faulting, Plutonism, Volcanism, and Hydrothermal Alteration

    USGS Publications Warehouse

    Cox, Dennis P.; Force, Eric R.; Wilkinson, William H.; More, Syver W.; Rivera, John S.; Wooden, Joseph L.

    2006-01-01

    Introduction: The Ajo porphyry copper deposit and surrounding Upper Cretaceous rocks have been separated from their plutonic source and rotated by detachment faulting. Overlying middle Cenozoic sedimentary and volcanic rocks have been tilted and show evidence for two periods of rotation. Following these rotations, a granitic stock (23.7?0.2 Ma) intruded basement rocks west of the Ajo deposit. This stock was uplifted 2.5 km to expose deep-seated Na-Ca alteration.

  2. Paleoproterozoic structural frame of the Yetti domain (Eglab shield, Algeria): Emplacement conditions of the Tinguicht late pluton from magnetic fabric study

    NASA Astrophysics Data System (ADS)

    Merabet, Nacer-eddine; Mahdjoub, Yamina; Henry, Bernard; Abtout, Abdeslam; Maouche, Said; Kahoui, Mohamed; Lamali, Atmane; Ayache, Mohamed

    2016-02-01

    The Tinguicht pluton is part of the ˜2.07 Ga post-collisional magmatic suites that intruded the Yetti Paleoproterozoic volcano-sedimentary series of the western part of the Eglab Shield (West African Craton). It represents one of the most recent units of these suites. This pluton, with a NW-SE elliptic shape, is unfoliated, and its deformational structures are practically restricted to fracturing and faulting. New structural, microstructural and aeromagnetic data are presented in order to analyze in particular the relationship between the Tinguicht pluton emplacement and the related NNW-SSE major mega-shear zone, separating the Yetti and Eglab domains. To constrain the context of the regional post-collisional evolution of the Eglab shield, a structural analysis was performed by mapping the magnetic structures (foliation and lineation) using AMS. The combination of the results of all the used approaches leads to a new and enriched image of this granitic pluton and of its tectonic emplacement context. The elliptic shape of the granitic body and the AMS strain pattern are consistent with the presence of a NNW-SSE major structure. NNW-SSE is also one of the major directions highlighted by the aeromagnetic data. This study thus evidences the role of the pre-existing major shear zones in controlling emplacement of post-collisional Paleoproterozoic plutons like Tinguicht, as shown for Drissa pluton in the Eglab domain earlier.

  3. Is the southeast Coast Plutonic Complex the consequence of accretion of the insular superterrane Evidence from U-Pb zircon geochronometry in the northern Washington Cascades

    SciTech Connect

    Walker, N.W. ); Brown, E.H. )

    1991-07-01

    Zircon U-Pb geochronometry of orthogneisses and plutons in the southwestern crystalline core of the North Cascades, coupled with fabric and textural studies of the orthogneisses, plutons, and their metamorphic host rocks, indicates extensive synmetamorphic plutonism at 89-96 Ma. Metamorphic mineral assemblages define a culmination composed of an axial kyanite-sillimanite zone rimmed by lower grade zones. High-grade index minerals are typically syntectonic to posttectonic. Metamorphic fabrics are characterized by an orogen-parallel, northwest-striking, steep foliation that contains a subhorizontal stretching and mineral lineation interpreted to be the product of ductile strike-slip deformation. This fabric is crosscut by 96-92 Ma plutons yet is imprinted on 92-89 Ma orthogneisses, suggesting spatially diachronous fabric development during orogeny. Documentation of the spatial and temporal coincidence of magmatism with the peak of orogeny, together with the kinematic significance of the metamorphic fabric, precludes generation of the metamorphic fabric and plutons in response to thrust loading. The authors suggest that this part of the Coast Plutonic Complex evolved as a transpressional magmatic arc.

  4. A tale of 10 plutons - Revisited: Age of granitic rocks in the White Mountains, California and Nevada

    USGS Publications Warehouse

    McKee, E.H.; Conrad, J.E.

    1996-01-01

    40Ar/39Ar incremental heating analysis and conventional K-Ar age determinations on plutonic rocks of the White Mountains define two stages of magmatic emplacement: Late Cretaceous, between ca. 90 Ma and 75 Ma, and Middle-Late Jurassic, between ca. 180 and 140 Ma. The Jurassic stage can be divided into two substages, 180-165 Ma and 150-140 Ma. Thermal effects of the younger plutons on the older granitoids partially to completely reset ages, making it difficult to determine the age of emplacement and cooling of several of the plutons even by 40Ar/39Ar incremental heating analyses. New data together with published ages and regional geochronological synthesis of the Sierra Nevada batholith indicate that regions within the batholith have coherent periods or episodes of magmatic activity. In the White Mountains and Sierra Nevada directly to the west there was little or no activity in Early Jurassic and Early Cretaceous time; magmatism took place during relatively short intervals of 15 m.y. or less in the Middle and Late Jurassic and Late Cretaceous periods. The new K-Ar and 40Ar/39Ar analyses of granitoids from the White Mountains help, but do not completely clarify the complex history of emplacement, cooling, and reheating of the batholith.

  5. The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins.

    PubMed

    Sommer, Carlos A; Lima, Evandro F; Nardi, Lauro V S; Liz, Joaquim D; Waichel, Breno L

    2006-09-01

    The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and calc-alkaline to shoshonitic and ended with a silica-saturated sodic alkaline magmatism, and its evolution were developed during at least 60 Ma. The compositional variation and evolution of post-collisional magmatism in southern Brazil are interpreted as the result mainly of melting of a heterogeneous mantle source, which includes garnet-phlogopite-bearing peridotites, veined-peridotites with abundant hydrated phases, such as amphibole, apatite and phlogopite, and eventually with the addition of an asthenospheric component. The subduction-related metasomatic character of post-collisional magmatism mantle sources in southern Brazil is put in evidence by Nb-negative anomalies and isotope features typical of EM1 sources. PMID:16936944

  6. Polychronous (Early Cretaceous to Palaeogene) emplacement of the Mundwara alkaline complex, Rajasthan, India: 40Ar/39Ar geochronology, petrochemistry and geodynamics

    NASA Astrophysics Data System (ADS)

    Pande, Kanchan; Cucciniello, Ciro; Sheth, Hetu; Vijayan, Anjali; Sharma, Kamal Kant; Purohit, Ritesh; Jagadeesan, K. C.; Shinde, Sapna

    2016-07-01

    The Mundwara alkaline plutonic complex (Rajasthan, north-western India) is considered a part of the Late Cretaceous-Palaeogene Deccan Traps flood basalt province, based on geochronological data (mainly 40Ar/39Ar, on whole rocks, biotite and hornblende). We have studied the petrology and mineral chemistry of some Mundwara mafic rocks containing mica and amphibole. Geothermobarometry indicates emplacement of the complex at middle to upper crustal levels. We have obtained new 40Ar/39Ar ages of 80-84 Ma on biotite separates from mafic rocks and 102-110 Ma on whole-rock nepheline syenites. There is no evidence for excess 40Ar. The combined results show that some of the constituent intrusions of the Mundwara complex are of Deccan age, but others are older and unrelated to the Deccan Traps. The Mundwara alkaline complex is thus polychronous and similar to many alkaline complexes around the world that show recurrent magmatism, sometimes over hundreds of millions of years. The primary biotite and amphibole in Mundwara mafic rocks indicate hydrous parental magmas, derived from hydrated mantle peridotite at relatively low temperatures, thus ruling out a mantle plume. This hydration and metasomatism of the Rajasthan lithospheric mantle may have occurred during Jurassic subduction under Gondwanaland, or Precambrian subduction events. Low-degree decompression melting of this old, enriched lithospheric mantle, due to periodic diffuse lithospheric extension, gradually built the Mundwara complex from the Early Cretaceous to Palaeogene time.

  7. Intermediate range order in alkaline borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Carini, G.; Ruello, G.; D'Angelo, G.

    2016-03-01

    We describe the neutron diffraction patterns of a series of alkaline borate glasses at different metal oxide content. Strong differences are observed in the intermediate range order as a function of the specific alkaline ion and of its concentration. On these results, we propose that the first sharp diffraction peak arises from correlations of atoms of voids and show that the compositional variation of this peak intensity in alkaline borate glasses is due to changes in the distribution of void sizes within the three-dimensional network. We argue that our interpretation in terms of interstitial (empty and/or filled) voids, having different sizes, provides a general explanation for all anomalous behaviours revealed for the first sharp diffraction peak.

  8. Late pleistocene and holocene history of the lakes in the Kola Peninsula, Karelia and the North-Western part of the East European plain

    NASA Astrophysics Data System (ADS)

    Davydova, N.; Servant-Vildary, S.

    The paper reviews the work on paleolimnology in parts of the FSU over the last 40 years. It presents a short review of The History of the Lakes of the East European Plain, one of the books of the series The History of Lakes published by the Institute of Lake Research of the Russian Academy of Sciences. It describes the Late Pleistocene and Holocene history of these lakes based mainly on the study of lacustrine sediments. Amongst the samples Lake Nero near Moscow which is located near the marginal zone of the last glaciation, and includes records that go back as early as 190,000 BP. The main elements of lake evolution are shown in different territories: Byelorussia; Baltic countries; Karelia; and the Kola Peninsula. Special attention is given to palaeolimnological data because its use for Holocene and Late Pleistocene palaeoclimate reconstructions.

  9. Alkaline Band Formation in Chara corallina

    PubMed Central

    Lucas, William J.

    1979-01-01

    The nature of the transport system responsible for the establishment of alkaline bands on cells of Chara corallina was investigated. The transport process was found to be insensitive to external pH, provided the value was above a certain threshold. At this threshold (pH 5.1 to 4.8) the transport process was inactivated. Transport function could be recovered by raising the pH value of the external solution. The fastest rate of recovery was always obtained in the presence of exogenous HCO3−. Experiments in which plasmalemma integrity was modified using 10 millimolar K+ treatment were also performed. Alkaline band transport was significantly reduced in the presence of 10 millimolar K+, but the system did not recover, following return to 0.2 millimolar K+ solutions, until the transport site was reexposed to exogenous HCO3−. The influence of presence and absence of various cations on both alkaline band transport and total H14CO3− assimilation was examined. No specific cation requirement (mono- or divalent) was found for either process, except the previously established role of Ca2+ at the HCO3− transport site. The alkaline band transport process exhibited a general requirement for cations. This transport system could be partially or completely stalled in low cation solutions, or glass-distilled water, respectively. The results indicate that no cationic flux occurs across the plasmalemma in direct association with either the alkaline band or HCO3− transport systems. It is felt that the present results offer support for the hypothesis that an OH− efflux transport system (rather than a H+ influx system) is responsible for alkaline band development in C. corallina. The results support the hypothesis that OH− efflux is an electrogenic process. This OH− transport system also appears to contain two allosteric effector sites, involving an acidic group and a HCO3− ion. PMID:16660706

  10. A petrologic comparison of Triassic plutonism in the San Gabriel and Mule Mountains, southern California

    SciTech Connect

    Barth, A.P. ); Tosdal, R.M.; Wooden, J.L. )

    1990-11-10

    Triassic magmatism in the southwest US Cordillera forms a semicontinuous magmatic arc extending from northwestern Nevada to southeastern California. Quartz monzodioritic and quartz monzonitic rocks and associated diorites and granites are widespread in southeastern California, and the authors suggest that these rocks represent exposure of a structurally deeper part of the Triassic arc, where it was emplaced into comparatively thick Proterozoic crust. Elemental and isotopic data suggest that Triassic quartz monzodiorites and quartz monzonites in the Mule and San Gabriel Mountains were derived from a relatively undepleted, nonradiogenic mafic lithospheric source, with virtually no upper crustal interaction. Very limited data for associated Triassic ( ) diorites indicate a wide range in composition and a surprisingly radiogenic isotopic signature. Younger Triassic( ) granites record a strong geochemical signature of interaction with continental crust, including inherited zircon and high initial Sr ratios but comparatively less radiogenic Pb isotopic compositions. The major and trace element geochemistry of Late Triassic plutonic rocks in southeastern California is similar in many respects to akalic components of the Triassic arc in the Mojave Desert. However, contemporaneous rocks farther north have a calc-alkalic signature, perhaps reflecting the variation in age and composition of lithosphere across which the Triassic arc was constructed.

  11. Geochemical Database for the Boulder Batholith and Its Satellitic Plutons, Southwest Montana

    USGS Publications Warehouse

    du Bray, Edward A.; Lund, Karen; Tilling, Robert I.; Denning, Paul D.; DeWitt, Ed

    2009-01-01

    Geochemical data presented in this report pertain to Cretaceous igneous intrusions of the Boulder batholith and its satellitic plutons in southwest Montana. The geographic area addressed in this compilation is approximately bounded by lats 45.6 deg and 46.7 deg N. and longs 112.75 deg and 111.5 deg W. These data were compiled in order to establish the geologic framework for world-class mineral deposits of the Butte district. Although these deposits and their host rocks have been the subject of many investigations, the petrologic characteristics of associated intrusive rocks have not been systematically compiled, synthesized, or interpreted. Abundant late Mesozoic intrusions in the study area are probably byproducts of subduction-related processes, including back-arc magmatism that prevailed along the west edge of the North American plate during this interval. The ultimate goal of this effort will be an evaluation of the time-space-compositional evolution of Mesozoic magmatism associated with the Boulder batholith and identification of genetic associations between magmatic and mineralizing processes in this region.

  12. Formation of lower continental crust by relamination of buoyant arc lavas and plutons

    NASA Astrophysics Data System (ADS)

    Kelemen, Peter B.; Behn, Mark D.

    2016-03-01

    The formation of the Earth's continents is enigmatic. Volcanic arc magmas generated above subduction zones have geochemical compositions that are similar to continental crust, implying that arc magmatic processes played a central role in generating continental crust. Yet the deep crust within volcanic arcs has a very different composition from crust at similar depths beneath the continents. It is therefore unclear how arc crust is transformed into continental crust. The densest parts of arc lower crust may delaminate and become recycled into the underlying mantle. Here we show, however, that even after delamination, arc lower crust still has significantly different trace element contents from continental lower crust. We suggest that it is not delamination that determines the composition of continental crust, but relamination. In our conceptual model, buoyant magmatic rocks generated at arcs are subducted. Then, upon heating at depth, they ascend and are relaminated at the base of the overlying crust. A review of the average compositions of buoyant magmatic rocks -- lavas and plutons -- sampled from the Aleutians, Izu-Bonin-Marianas, Kohistan and Talkeetna arcs reveals that they fall within the range of estimated major and trace elements in lower continental crust. Relamination may thus provide an efficient process for generating lower continental crust.

  13. Natural radioactivity distribution and gamma radiation exposure of beach sands close to Kavala pluton, Greece

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Argyrios; Koroneos, Antonios; Christofides, Georgios; Stoulos, Stylianos

    2015-10-01

    This study aims to evaluate the activity concentrations of 238U, 226Ra, 232Th, 228Th and 40K along the beaches of Kavala being adjacent to the rock-types of the Kavala pluton. These ranged from 14-940, 16-1710, 26- 4547, 27-4488 and 194-1307 Bq/kg respectively, representing the highest values of natural radioactivity measured in sediments of Greece. The (%wt.) heavy magnetic (HM) (allanite, amphibole, mica, clinopyroxene, magnetite and hematite) fraction, the heavy non-magnetic (HNM) (monazite, zircon, titanite and apatite) fraction and the total heavy fraction (TH), were correlated with the concentrations of the measured radionuclides in the bulk samples. The heavy fractions seem to control the activity concentrations of 238U and 232Th of all the samples, showing some local differences in the main 238U and 232Th mineral carrier. The measured radionuclides in the beach sands were normalized to the respective values measured in the granitic rocks, which are their most probable parental rocks, so as to provide data upon their enrichment or depletion. The annual equivalent dose varies between 0.01 and 0.35 mSv y-1 for tourists and from 0.03 to 1.48 mSv y-1 for local people working on the beach.

  14. Phase equilibria of a fluorine-rich leucogranite from the St. Austell pluton, Cornwall

    SciTech Connect

    Weidner, J.R.; Martin, R.F.

    1987-06-01

    Highly evolved leucogranitic rocks in the St. Austell pluton, Cornwall, of Hercynian age, contain accessory muscovite, topaz and fluorite. The authors have studied the H/sub 2/O-saturated melting behavior of one representative sample. Its solidus and liquidus pass through the points 663 and 725/sup 0/C, respectively, at 1 kbar, 640 and 665/sup 0/C at 2 kbar, 610 and 717/sup 0/C at 4 kbar, and 608 and 700+/sup 0/C at 8 kbar. Plagioclase is on the liquidus at low pressure, and topaz is on the liquidus at 4 kbar. The fluorite is consumed in the formation of the first-formed liquid. Calcium can partition into an evolved granitic melt if complexed by fluorine. The fluorite appears to be largely primary in fresh fluorite granite at St. Austell, and not to reflect the albitization of oligoclase in the surrounding biotite granite. Such fluorine-rich leucogranites can be expected to be of subsolvus character.

  15. Metamorphism and plutonism in the Quetico Belt, Superior Province, N.W. Ontario

    NASA Technical Reports Server (NTRS)

    Percival, J. A.

    1986-01-01

    The Quetico Belt lies between the metavolcanic Wawa-Shebandowan and Wabigoon Belts. It consists of marginal metasedimentary rocks and central pelitic, gneissic and plutonic rocks. Metamorphism is Barrovian, at depths less than 10 km, and grade increases from margins to core of the belt: the outermost pelites are at chlorite-muscovite grade; inward a garnet-andalusite zone formed throughout the inner margin; and the central zone ranges form garnet-andalusite in the west and garnet-sillimanite-muscovite to garnet-sillimanite-cordierite and rare kyanite 6 to 150 km to the east. This increase is correlated with granitic intrusives. Migmatites in the core have intrusive leucosomes in the west and locally derived ones in the east. Isograd surfaces are steep where the belt is narrow and dip gently where it is wide. The Quetico Park intrusive complex of the central region of the Quetico Belt shows a zonation across it 20 to 50 km width from older, medium grained biotite composition to younger, coarse to pegmatitic granitic composition. Sediment of the Quetico basin had its source in the bordering metavolcanic belts and was deposited ca. 2.75 to 2.70 Ga ago. Boundaries of the belt dip inward, so it essentially is a graben of inter-arc or back-arc type.

  16. Distribution of manganese between coexisting biotite and hornblende in plutonic rocks

    USGS Publications Warehouse

    Greenland, L.P.; Gottfried, D.; Tilling, R.I.

    1968-01-01

    The distribution of manganese between coexisting biotite and hornblende for 80 mineral pairs from igneous rocks of diverse provenance (including Southern California, Sierra Nevada, Boulder, and Boulder Creek batholiths and the Jemez Mountains volcanics) has been determined by neutron activation analysis. Data on the distribution ratio (Kd = Mnhornblende Mnbiotite) indicate that an equilibrium distribution of Mn is closely approached, though not completely attained, in most samples from plutonic environments. Comparison of Kd values of mineral pairs with bulk chemical composition of host rocks reveals no correlation. Because initial crystallization temperatures vary with rock composition, the lack of correlation of composition with Kd suggests that the equilibrium distribution of Mn between biotite and hornblende reflects exchange at subsolidus temperatures rather than initial crystallization temperatures. The highest Kd values are for volcanic rocks, in which rapid quenching prevents subsolidus redistribution of Mn. For sample pairs from the Southern California and Sierra Nevada batholiths there is a positive correlation of Kd with TiO2 content of biotite. Though the evidence is not compelling, Kd may also correlate with the rate of cooling and/or the presence or absence of sphene in the rock. ?? 1968.

  17. High Resolution Images of the Granitic Plutons Along the Iberseis Deep Seismic Reflection Transect: Southwestern Iberia

    NASA Astrophysics Data System (ADS)

    Palomeras, I.; Flecha, I.; Simacas, F.; Gonzalez-Lodeiro, F.; Carbonell, R.

    2006-12-01

    IBERSEIS is a 303 Km long deep seismic profile in the S-W of Iberian Peninsula. The parameters used for the acquisition allow for a high resolution imaging of the shallow subsurface. The deep seismic transect goes across several characteristic granitic plutons. Detailed imaging of these outcropping granites and the neighboring geologic structures has been attempted. The trace of the profile followed roads and paths, resulting in a irregular acquisition geometry. The quality of the final image is improved considerably by using crooked line techniques which took into account the irregular distribution of sources and receivers. The rugged topography which can reach more than 300 m height and the highly heterogeneous surface geology required carefully estimated static corrections. Reliable shallow velocity models were obtained by first arrival travel time tomographic inversions. These velocity models were also used for pre-stack depth migration imaging. The reprocessing improved the seismic reflection images allowing for a better geological interpretation and, in some cases, provide a direct correlation between the surface geology and the imaged features. The imaged structures suggest possible emplacement mechanisms.

  18. Degradation of halogenated carbons in alkaline alcohol

    NASA Astrophysics Data System (ADS)

    Nakagawa, Seiko; Shimokawa, Toshinari

    2002-02-01

    1,1,2-Trichloro-trifluoroethane, 1,2-dibromo-tetrafluoroethane, 2,3,4,6-tetrachlorophenol, 1,2,4-trichlorobenzene, and 2,4,6-trichloroanisole were dissolved in alkaline isopropyl alcohol and irradiated with 60Co gamma rays after purged with pure nitrogen gas. The concentration of the hydroxide ions and the parent molecules decreased with the dose, while that of the halide ions and the organic products, with less halogen atoms than the parent, increased. Chain degradation will occur in alkaline isopropyl alcohol.

  19. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    DOEpatents

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  20. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  1. Alkaline Capacitors Based on Nitride Nanoparticles

    NASA Technical Reports Server (NTRS)

    Aldissi, Matt

    2003-01-01

    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  2. Identification of the AntiListerial Constituents in Partially Purified Column Chromatography Fractions of Garcinia kola Seeds and Their Interactions with Standard Antibiotics

    PubMed Central

    Penduka, D.; Buwa, L.; Mayekiso, B.; Basson, A. K.; Okoh, A. I.

    2014-01-01

    Partially purified fractions of the n-hexane extract of Garcinia kola seeds were obtained through column chromatography and their constituents were identified through the use of gas chromatography coupled to mass spectrometry (GC-MS). Three fractions were obtained by elution with benzene as the mobile phase and silica gel 60 as the stationery phase and these were named Benz1, Benz2, and Benz3 in the order of their elution. The antiListerial activities of these fractions were assessed through MIC determination and only Benz2 and Benz3 were found to be active with MIC's ranging from 0.625 to 2.5 mg/mL. The results of the GC-MS analysis showed Benz2 to have 9 compounds whilst Benz3 had 7 compounds, with the major compounds in both fractions being 9,19-Cyclolanost-24-en-3-ol, (3.β.) and 9,19-Cyclolanostan-3-ol,24-methylene-, (3.β.). The Benz2 fraction was found to have mainly indifferent interactions with ampicillin and penicillin G whilst mainly additive interactions were observed with ciprofloxacin. The Benz3 fraction's interactions were found to be 50% synergistic with penicillin G and 25% synergistic with ciprofloxacin and ampicillin. A commercially available 9,19-Cyclolanost-24-en-3-ol, (3.β.) was found not to exhibit any antiListerial activities at maximum test concentrations of 5 mg/mL, suggesting that the compound could be acting in synergy with the other compounds in the eluted fractions of Garcinia kola seeds. PMID:24527056

  3. Identification of the AntiListerial Constituents in Partially Purified Column Chromatography Fractions of Garcinia kola Seeds and Their Interactions with Standard Antibiotics.

    PubMed

    Penduka, D; Buwa, L; Mayekiso, B; Basson, A K; Okoh, A I

    2014-01-01

    Partially purified fractions of the n-hexane extract of Garcinia kola seeds were obtained through column chromatography and their constituents were identified through the use of gas chromatography coupled to mass spectrometry (GC-MS). Three fractions were obtained by elution with benzene as the mobile phase and silica gel 60 as the stationery phase and these were named Benz1, Benz2, and Benz3 in the order of their elution. The antiListerial activities of these fractions were assessed through MIC determination and only Benz2 and Benz3 were found to be active with MIC's ranging from 0.625 to 2.5 mg/mL. The results of the GC-MS analysis showed Benz2 to have 9 compounds whilst Benz3 had 7 compounds, with the major compounds in both fractions being 9,19-Cyclolanost-24-en-3-ol, (3. β .) and 9,19-Cyclolanostan-3-ol,24-methylene-, (3. β .). The Benz2 fraction was found to have mainly indifferent interactions with ampicillin and penicillin G whilst mainly additive interactions were observed with ciprofloxacin. The Benz3 fraction's interactions were found to be 50% synergistic with penicillin G and 25% synergistic with ciprofloxacin and ampicillin. A commercially available 9,19-Cyclolanost-24-en-3-ol, (3. β .) was found not to exhibit any antiListerial activities at maximum test concentrations of 5 mg/mL, suggesting that the compound could be acting in synergy with the other compounds in the eluted fractions of Garcinia kola seeds. PMID:24527056

  4. The Pan-African high-K calc-alkaline peraluminous Elat granite from southern Israel: geology, geochemistry and petrogenesis

    NASA Astrophysics Data System (ADS)

    Eyal, M.; Litvinovsky, B. A.; Katzir, Y.; Zanvilevich, A. N.

    2004-10-01

    Calc-alkaline leucocratic granites that were emplaced at the late post-collision stage of the Pan-African orogeny are abundant in the northern half of the Arabian-Nubian Shield. Commonly, they are referred to as the Younger Granite II suite. In southern Israel such rocks are known as Elat granite. Studies of these rocks enable to recognize two types of granites: coarse-grained, massive Elat granite (EG), and fine- to medium-grained Shahmon gneissic granite (SGG). Both granite types are high-K and peraluminous ( ASI ranges from 1.03 to 1.16). They are similar in modal composition, mineral and whole-rock chemistry. Within the EG, a noticeable distinction in whole-rock chemistry and mineral composition is observed between rocks making up different plutons. In particular, the granite of Wadi Shelomo, as compared to the Rehavam pluton, is enriched in SiO 2, FeO∗, K 2O, Ba, Zr, Th, LREE and impoverished in MgO, Na 2O, Sr, and HREE. The Eu/Eu∗ values in the granite are low, up to 0.44. Mass-balance calculations suggest that chemical and mineralogical variations were caused by fractionation of ˜16 wt.% plagioclase from the parental Rehavam granite magma at temperature of 760-800 °C (muscovite-biotite geothermometer). The Rb-Sr isochrons yielded a date of 623 ± 24 Ma for the EG, although high value of age-error does not allow to constrain time of emplacement properly. The Rb-Sr date for SGG is 640 ± 9 Ma; however, it is likely that this date points to the time of metamorphism. A survey of the literature shows that peraluminous, high-K granites, similar to the EG, are abundant among the Younger Granite II plutons in the Sinai Peninsula and Eastern Desert, Egypt. They were emplaced at the end of the batholithic (late post-collision) stage. The most appropriate model for the generation of the peraluminous granitic magma is partial melting of metapelite and metagreywacke.

  5. Quartz and feldspar zoning in the eastern Erzgebirge volcano-plutonic complex (Germany, Czech Republic): evidence of multiple magma mixing

    NASA Astrophysics Data System (ADS)

    Müller, Axel; Breiter, Karel; Seltmann, Reimar; Pécskay, Zoltán

    2005-03-01

    Zoned quartz and feldspar phenocrysts of the Upper Carboniferous eastern Erzgebirge volcano-plutonic complex were studied by cathodoluminescence and minor and trace element profiling. The results verify the suitability of quartz and feldspar phenocrysts as recorders of differentiation trends, magma mixing and recharge events, and suggest that much heterogeneity in plutonic systems may be overlooked on a whole-rock scale. Multiple resorption surfaces and zones, element concentration steps in zoned quartz (Ti) and feldspar phenocrysts (anorthite content, Ba, Sr), and plagioclase-mantled K-feldspars etc. indicate mixing of silicic magma with a more mafic magma for several magmatic phases of the eastern Erzgebirge volcano-plutonic complex. Generally, feldspar appears to be sensitive to the physicochemical changes of the melt, whereas quartz phenocrysts are more stable and can survive a longer period of evolution and final effusion of silicic magmas. The regional distribution of mixing-compatible textures suggests that magma mingling and mixing was a major process in the evolution of these late-Variscan granites and associated volcanic rocks. Quartz phenocrysts from 14 magmatic phases of the eastern Erzgebirge volcano-plutonic complex provide information on the relative timing of different mixing processes, storage and recharge, allowing a model for the distribution of magma reservoirs in space and time. At least two levels of magma storage are envisioned: deep reservoirs between 24 and 17 km (the crystallisation level of quartz phenocrysts) and subvolcanic reservoirs between 13 and 6 km. Deflation of the shallow reservoirs during the extrusion of the Teplice rhyolites triggered the formation of the Altenberg-Teplice caldera above the eastern Erzgebirge volcano-plutonic complex. The deep magma reservoir of the Teplice rhyolite also has a genetic relationship to the younger mineralised A-type granites, as indicated by quartz phenocryst populations. The pre

  6. The features of element concentration in natural waters of the Kola North in conditions of environmental contamination

    NASA Astrophysics Data System (ADS)

    Bazova, Mariya; Moiseenko, Tatyana

    2016-04-01

    The intensive use of fossil fuels and industrial development in last century led to the formation of acid rain and water acidification. The problem of water acidification greatly was denoted in the middle of last century in North America and in Europe as a result of air emissions of acid gases, primarily sulfur dioxide. The process of water acidification due to the interaction of two factors: 1) the high deposition of acidifying substances, taking into account the duration of exposure; 2) the sensitivity of the natural catchment area of geological, landscape, geographic and climatic characteristics (Moiseenko, 2005). The effects of acid rains on metal migration and cycling were discussed in a number of previous studies (Jeffries, 1997; Moiseenko, 1999; Manio, 2001; Moiseenko, Gashkina, 2007). The distribution of elements in water lakes has been mixed and due to the change of geochemical cycles of elements occurring in the catchment area and in water. On the Kola Peninsula as a result of long-term operation of the copper-nickel smelter was the anthropogenic acidification and water pollution metals. Increased contents of elements due to the combined effect of three factors: 1) landscape-geochemical characteristics of watersheds; 2) dispersion with flue emissions; 3) leaching elements and bonding of metals with organic matter, especially in forested watersheds and wetlands. This region is subject to long-term effects of mining and smelting industries, and therefore difficult to find of water bodies, which can serve as a background lakes. It is proved that manmade acid rain lead to leach into the water of a large group of elements entering the water as a result of man-made streams, as well as the elements that consist of the rocks forming the watersheds. In order to identify the relationships between the components of the elemental composition of the water in the lake was made a factor analysis using a computer program «STATISTICA 10". Factor analysis revealed the

  7. Timing and origin of midcontinent rift alkaline magmatism, North America: evidence from the Coldwell Complex

    NASA Astrophysics Data System (ADS)

    Heaman, L. M.; Machado, N.

    1992-04-01

    The Coldwell Complex represents the largest alkaline intrusion associated with the Midcontinent Rift System in North America. This complex contains a plethora of rock types that have previously been subdivided into three intrusive centers. A detailed U-Pb zircon/baddeleyite age study of five samples indicates that the majority of the complex was emplaced into “cold” Archean crust at 1108±1 Ma and likely experienced a rapid cooling history. These data, combined with published U-Pb zircon/baddeleyite results for other rift related igneous activity, document the contemporaneous production and emplacement of tholeiitic and alkaline magmas at the onset of rifting. The Sr-Nd-Pb isotopic compositions of selected minerals from different phases of the complex display considerable scatter that is best explained by the presence of magmas with different initial isotopic compositions. The initial Sr and Nd isotopic compositions for clinopyroxene and plagioclase from one of the earliest gabbro phases (ɛNd=+0.5 to +1.6; ɛSr=+2.4 to +3.1) are identical to published data for primitive olivine tholeiites from the rift and indicate that the majority of magmas, both tholeiitic and alkaline, have a uniform, nearly chondritic isotopic composition. This very reproducible isotopic composition for rift magmatism can be explained by the dominance of a well-mixed mantle plume signature in magma genesis. The shift in isotopic compositions observed for the more evolved granite and syenite samples (ɛNd=-4.6 to -6.4; ɛSr=+10.2 to +13.8) combined with a less radiogenic Pb isotopic signature is consistent with derivation of these magmas from or interaction with an older granulite facies lower crust. The chondritic isotopic signature typical of most MRS volcanic and plutonic rocks is quite distinct from published results on associated carbonatites (ɛNd=+2.1 to +4.5; ɛSr=-8.0 to 2212;11.5) indicating the presence of at least two distinct subcontinental mantle isotopic reservoirs in this

  8. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    PubMed Central

    Schwalfenberg, Gerry K.

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine. PMID:22013455

  9. Crystallization conditions of porphyritic high-K calc-alkaline granitoids in the extreme northeastern Borborema Province, NE Brazil, and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Campos, Benedita Cleide Souza; Vilalva, Frederico Castro Jobim; Nascimento, Marcos Antônio Leite do; Galindo, Antônio Carlos

    2016-10-01

    An integrated textural and chemical study on amphibole, biotite, plagioclase, titanite, epidote, and magnetite was conducted in order to estimate crystallization conditions, along with possible geodynamic implications, for six Ediacaran porphyritic high-K calc-alkaline granite plutons (Monte das Gameleiras, Barcelona, Acari, Caraúbas, Tourão, and Catolé do Rocha) intrusive into Archean to Paleoproterozoic rocks of the São José do Campestre (SJCD) and Rio Piranhas-Seridó (RPSD) domains, northern Borborema Province. The studied rocks include mainly porphyritic leucocratic monzogranites, as well as quartz-monzonites and granodiorites. Textures are marked by K-feldspar megacrysts (5-15 cm long) in a fine-to medium-grained matrix composed of quartz, plagioclase, amphibole, biotite, as well as titanite, epidote, Fesbnd Ti oxides, allanite, apatite, and zircon as accessory minerals. Amphibole, biotite and titanite share similar compositional variations defined by increasing Al and Fe, and decreasing Mg contents from the plutons emplaced into the SJCP (Monte das Gameleiras and Barcelona) towards those in the RPSD (Acari, Caraúbas, Tourão, and Catolé do Rocha). Estimated intensive crystallization parameters reveal a weak westward range of increasing depth of emplacement, pressure and temperature in the study area. The SJCD plutons (to the east) crystallized at shallower crustal depths (14-21 km), under slightly lower pressure (3.8-5.5 kbar) and temperature (701-718 °C) intervals, and high to moderate oxygen fugacity conditions (+0.8 < ΔFQM < +2.0). On the other hand, the RPSD plutons (to the west) were emplaced at slightly deeper depths (18-23 km), under higher, yet variable pressures (4.8-6.2 kbar), temperatures (723-776 °C), and moderate to low oxygen fugacity conditions (-1.0 < ΔFQM < +1.8). These results reinforce the contrasts between the tectono-strutuctural domains of São José do Campestre and Rio Piranhas-Seridó in the northern Borborema Province.

  10. Multiple origins for the Middle Jurassic to Early Cretaceous high-K calc-alkaline I-type granites in northwestern Fujian province, SE China and tectonic implications

    NASA Astrophysics Data System (ADS)

    Wang, Guo-Chang; Jiang, Yao-Hui; Liu, Zheng; Ni, Chun-Yu; Qing, Long; Zhang, Qiao; Zhu, Shu-Qi

    2016-03-01

    A comprehensive study of zircon U-Pb dating and in situ Hf isotopes, whole-rock major and trace element geochemistry and Sr-Nd isotopes was carried out for three late Mesozoic granitic plutons (Waitun, Shipi and Taiyuan) in northwestern Fujian province, SE China. We assess the origin of the granites and their relationship to the evolution of the late Mesozoic volcanic-intrusive complex belt in SE China. LA-ICP-MS zircon U-Pb dating shows that three plutons were emplaced in the Middle Jurassic to Early Cretaceous (168-109 Ma), in which the Waitun and Shipi plutons are intrusive complexes. All the plutons are composed of high-K calc-alkaline I-type granites with a great diversity in elemental and isotopic compositions. The granites have SiO2 contents of 68.3-78.5 wt.%, showing a gradual decrease in initial 87Sr/86Sr (0.7181 to 0.7091) and increase in εNd (T) (- 16.7 to - 8.1) and εHf (T) (in-situ zircon) (- 20.6 to - 6.9) with decreasing emplacement ages. Geochemical data suggest that the Middle Jurassic (~ 168 Ma) Waitun granites are of purely crustal origin, derived by partial melting of a mixed source of Paleoproterozoic metaigneous (~ 78%) and metasedimentary (~ 22%) rocks at a depth of 30-40 km triggered by underplating of basaltic magma. Mixing of such crustal melts with about 10% basaltic magma could account for the origin of the Late Jurassic (~ 161 Ma) Waitun granites. The Late Jurassic (~ 156 Ma) Shipi and Early Cretaceous (~ 134 Ma) Taiyuan granites were produced by extensive fractional crystallization of primary crustal melts, the source of which show relatively high proportion (~ 82%) of metaigneous rocks. The Early Cretaceous (~ 109 Ma) Shipi granites were generated by partial melting of a mixed source of Paleoproterozoic metaigneous (~ 92%) and metasedimentary (~ 8%) rocks at a depth of ~ 30 km plus additional (~ 15%) input from coeval basaltic magma. The granites were formed in a continental arc setting induced by northwestward subduction of the

  11. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  12. Negative Electrode For An Alkaline Cell

    DOEpatents

    Coco, Isabelle; Cocciantelli, Jean-Michel; Villenave, Jean-Jacques

    1998-07-14

    The present invention concerns a negative electrode for an alkaline cell, comprising a current collector supporting a paste containing an electrochemically active material and a binder, characterized in that said binder is a polymer containing hydrophilic and hydrophobic groups, said polymer being selected from an acrylic homopolymer, copolymer and terpolymer, an unsaturated organic acid copolymer and an unsaturated acid anhydride copolymer.

  13. Kinetics of the alkaline hydrolysis of nitrocellulose.

    PubMed

    Christodoulatos, C; Su, T L; Koutsospyros, A

    2001-01-01

    Cellulose nitrate (nitrocellulose) is an explosive solid substance used in large quantities in various formulations of rocket and gun propellants. Safe destruction of nitrocellulose can be achieved by alkaline hydrolysis, which converts it to biodegradable products that can then be treated by conventional biological processes. The kinetics of the alkaline hydrolysis of munitions-grade nitrocellulose in sodium hydroxide solutions were investigated in completely mixed batch reactors. Experiments were conducted using solutions of alkaline strength ranging from 0.1 to 15% by mass and temperatures in the range of 30 to 90 degrees C. Regression analysis of the kinetic data revealed that alkaline hydrolysis of nitrocellulose is of the order 1.0 and 1.5 with respect to nitrocellulose and hydroxide concentration, respectively. The activation energy of the hydrolysis reaction was found to be 100.9 kJ/mol with a preexponential Arrhenius constant of 4.73 x 10(13). Nitrite and nitrate, in a 3:1 ratio, were the primary nitrogen species present in the posthydrolysis solution. The kinetic information is pertinent to the development and optimization of nitrocellulose chemical-biological treatment systems. PMID:11563378

  14. Use Alkalinity Monitoring to Optimize Bioreactor Performance.

    PubMed

    Jones, Christopher S; Kult, Keegan J

    2016-05-01

    In recent years, the agricultural community has reduced flow of nitrogen from farmed landscapes to stream networks through the use of woodchip denitrification bioreactors. Although deployment of this practice is becoming more common to treat high-nitrate water from agricultural drainage pipes, information about bioreactor management strategies is sparse. This study focuses on the use of water monitoring, and especially the use of alkalinity monitoring, in five Iowa woodchip bioreactors to provide insights into and to help manage bioreactor chemistry in ways that will produce desirable outcomes. Results reported here for the five bioreactors show average annual nitrate load reductions between 50 and 80%, which is acceptable according to established practice standards. Alkalinity data, however, imply that nitrous oxide formation may have regularly occurred in at least three of the bioreactors that are considered to be closed systems. Nitrous oxide measurements of influent and effluent water provide evidence that alkalinity may be an important indicator of bioreactor performance. Bioreactor chemistry can be managed by manipulation of water throughput in ways that produce adequate nitrate removal while preventing undesirable side effects. We conclude that (i) water should be retained for longer periods of time in bioreactors where nitrous oxide formation is indicated, (ii) measuring only nitrate and sulfate concentrations is insufficient for proper bioreactor operation, and (iii) alkalinity monitoring should be implemented into protocols for bioreactor management. PMID:27136151

  15. ISSUES WITH ALKALINE TREATMENT OF SLUDGE

    EPA Science Inventory

    This presentation begins with a discussion of the use of lime and other alkaline materials from the very earliest times to the present for killing bacteria, viruses and parasites and for controlling odors in wastewaters and sludge. It answers the question "How did EPA arrive at i...

  16. Alkaline electrochemical cells and method of making

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    Equilibrated cellulose ether membranes of increased electrolytic conductivity for use as separators in concentrated alkaline electrochemical cells are investigated. The method of making such membranes by equilibration to the degree desired in an aqueous alkali solution mantained at a temperature below about 10 C is described.

  17. Titanium corrosion in alkaline hydrogen peroxide environments

    NASA Astrophysics Data System (ADS)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  18. Late magmatic stage of the zoned Caleu pluton (Central Chile): insights from zircon crystallization conditions

    NASA Astrophysics Data System (ADS)

    Molina, P. G.; Parada, M.; Gutierrez, F. J.; Chang-Qiang, M.; Jianwei, L.; Yuanyuan, L.

    2012-12-01

    The Caleu pluton consists of three N-S elongated lithological zones: Gabbro-Diorite Zone (GDZ), Tonalite Zone (TZ) and Granodiorite Zone (GZ); western, middle and eastern portions of the pluton, respectively. The zones are thought to be previously differentiated in a common, isotopically depleted (Sr-Nd), subjacent magma reservoir at a 4 kbar equivalent depth. The emplacement should have occurred at the climax of the Cretaceous rifting. We present preliminary results of U238/Pb206 zircon geochronology; zircon saturation, Tsat(Zrn), and crystallization temperatures (Ti-in-Zrn); as well as relative oxidation states at time of crystallization, based on: (i) the sluggish REE and HFSE subsolidus diffusivities in zircon; (ii) the behavior of Ti4+↔Si4+ and Ce4+↔Zr4+ isovalent replacement, in addition to a constrained TiO2 activity in almost all typical crustal rocks; and (iii) relative oxidation states at time of crystallization, respectively. The latter are obtained by interpolation of the partition coefficients of trivalent (REE) and tetravalent (HFSE) curves in Onuma diagrams for each zircon, and then estimating relative Ce(IV)/Ce(III) ratios. Results obtained from 4 samples (a total of 77 zircon grains) collected from the three mentioned lithological zones indicate U/Pb ages of approximately 99.5 ±1.5 Ma, 96.8 ±0.6 Ma, and 94.4 +2.2 -0.8 Ma; and Ti-in Zrn ranges of ca. 720-870°C, ca. 680-820°C and ca. 750-840°C, for the GDZ, TZ and GZ samples, respectively. On the other hand Tsat(Zrn) of ca. 750-780°C in the TZ, and ca. 830-890°C in the GZ, were obtained. As expected saturation temperatures are similar or higher than Ti-in-Zrn obtained in zircon grains of TZ and GZ, respectively. Cathodoluminiscence images in zircon suggest a magmatic origin, due to absence of complex zoning patterns and fairly well conserved morphologies. Exceptionally the GDZ sample zircons show evidence of inheritance, indicating a xenocrystic and/or antecrystic origin. A relative Ce

  19. Poly-phase Deformation Recorded in the Core of the Coast Plutonic Complex, Western British Columbia

    NASA Astrophysics Data System (ADS)

    Hamblock, J. M.; Andronicos, C. L.; Hurtado, J. M.

    2006-05-01

    The Coast Plutonic Complex of western British Columbia constitutes the largest batholith within the North American Cordillera. The field area for this study is Mt. Gamsby, an unexplored region above the Kitlope River, east of the Coast Shear Zone and at the southern end of the Central Gneiss Complex. The dominant lithologies on Mt. Gamsby include amphibolite and metasedimentary gneiss, gabbro-diorite, and orthogneiss. The amphibolite gneiss contains alternating amphibolite and felsic layers, with chlorite and epidote pervasive in some regions and garnet rare. This unit is commonly migmatized and contains various folds, boudins, and shear zones. The metasedimentary gneiss contains quartz, k-spar, graphite, chlorite, and perhaps cordierite, but appears to lack muscovite and aluminosilicates. The gabbro-diorite is salt and pepper in color and contains ca. 50% pyroxene and plagioclase. The orthogneiss is light in color and plagioclase-rich, with a texture varying from coarse-grained and undeformed to mylonitic. In some regions, this unit contains abundant mafic enclaves. At least four deformational events (D1-4) are observed. The second generation of folding, F2, is dominant in the area and resulted in the production of a large synform during sinistral shearing. The S1 foliation is observed only in the amphibolite gneiss and is orthogonal to S2, creating mushroom- type fold interference patterns. S2 foliations strike NW-SE and dip steeply to the SW, suggesting SW-NE directed shortening. L2 lineations developed on S2 plunge shallowly to the NW and SE, implying strike-slip motion. Although both dextral and sinistral motions are indicated by shear band data, sinistral motion is dominant. The average right and left lateral shear band orientation is nearly identical to S2, suggesting that right and left lateral shearing were synchronous. Foliations within the orthogneiss are parallel to the axes of S2 folds and boudins in the amphibolite gneiss, suggesting that emplacement

  20. Growth of a Large Composite Magma System: the EJB Pluton, Eastern California.

    NASA Astrophysics Data System (ADS)

    Matty, D. J.; Vervoort, J.; Dufrane, A.; Hart, G.; Student, J.; Morgan, S.

    2008-12-01

    The composite EJB pluton crops out in the White-Inyo Mountains of eastern California, and comprises the Eureka Valley monzonite (EVM), the Joshua Flat quartz monzonite (JFQM), the Beer Creek granite (BCG), and an unnamed diorite. While sometimes equivocal, field relationships suggest that the EVM was emplaced first, followed by the JFQM, and finally the BCG; the diorite predates the BCG. Sylvester and others (GSAB, 1978) reported zircon U-Pb ages of 179±2 Ma for the EVM and 174±5 Ma for the JFQM. Coleman and others (GSAB, 2003) determined a U-Pb age of 179±3 Ma (via Pb-loss trajectory) for the BCG. Because of the uncertainty in the ages and ambiguous field relations, the sequence and duration of EJB magmatism remain unclear. To understand more fully the timing of EJB magmatism, we separated zircons from 12 samples collected from each of the main EJB units. These samples were characterized using light microscopy, SEM and CL techniques. U-Pb ages were determined from individual zircons by LA-ICP-MS following the method of Chang and others (G3, 2006). For the ages reported below, the reported uncertainties are based on factors within the analysis, but do not include external factors such as sample/standard bias or other matrix effects. Overall uncertainty in LA-ICPMS U-Pb geochronology is hard to assess, but we estimate that all ages reported below are subject to a minimum 2% uncertainty. We determined a concordant U-Pb age of 180±2 Ma for the EVM, which agrees with the results of Sylvester and others (1978). The unnamed diorite produced a concordant U-Pb age of 177±3 Ma. Concordant U-Pb ages of 172±2, 172±3, 173±2, 174±2, and 175±2 Ma were determined for individual samples of the JFQM and agree with the age reported by Sylvester and others (1978) of 174±5 Ma. Concordant U-Pb ages of 168±4, 168±3, 169±1, 172±2, and 172±2 Ma were determined for individual BCG samples. Within the reported error, there is no difference in age between individual samples of

  1. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am - the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting ...

  2. A method for making an alkaline battery electrode plate

    NASA Technical Reports Server (NTRS)

    Chida, K.; Ezaki, T.

    1983-01-01

    A method is described for making an alkaline battery electrode plate where the desired active substances are filled into a nickel foam substrate. In this substrate an electrolytic oxidation reduction occurs in an alkaline solution containing lithium hydroxide.

  3. Multi-sensor geophysical constraints on crustal melt in the central Andes: the PLUTONS project

    NASA Astrophysics Data System (ADS)

    Pritchard, M. E.; Comeau, M. J.; West, M. E.; Christensen, D. H.; Mcfarlin, H. L.; Farrell, A. K.; Del Potro, R.; Gottsmann, J.; McNutt, S. R.; Michelfelder, G.; Diez, M.; Elliott, J.; Henderson, S. T.; Keyson, L.; Delgado, F.; Unsworth, M. J.

    2015-12-01

    The central Andes is a key global location to quantify storage, transport, and volumes of magma in the Earth's crust as it is home to the world's largest zone of partial melt (the Altiplano-Puna Magma or Mush Body, APMB) as well as the more recently documented Southern Puna Magma Body (SPMB). We describe results from the recently completed international PLUTONS project that focused inter-disciplinary study on two sites of large-scale surface uplift that presumably represent ongoing magmatic intrusions in the mid to upper crust - Uturuncu, Bolivia (in the center of the APMB) and Lazufre on the Chile-Argentina border (on the edge of the SPMB). In particular, a suite of geophysical techniques (seismology, gravity, surface deformation, and electro-magnetic methods) have been used to infer the current subsurface distribution and quantity of partial melts in combination with geochemical and lab studies on samples from the area. Both Uturuncu and Lazufre show separate geophysical anomalies in the upper and mid/lower crust (e.g., low seismic velocity, low resistivity, etc.) indicating multiple distinct reservoirs of magma and/or hydrothermal fluids with different properties. The characteristics of the geophysical anomalies differ somewhat depending on the technique used - reflecting the different sensitivity of each method to subsurface melt of different compositions, connectivity, and volatile content. For example, the depth to the top of the APMB is shallower in a joint ambient noise tomography and receiver function analysis compared to a 3D magnetotelluric inversion. One possibility is that the seismic methods are detecting brines above the APMB that do not have a large electromagnetic signature. Comparison of the geophysical measurements with laboratory experiments at the APMB indicate a minimum of 4-25% melt averaged over the region is needed -- higher melt volumes are permitted by the gravity and MT data and may exist in small regions. However, bulk melt values above

  4. Geologic and hydrologic controls on the economic potential of hydrothermal systems associated with upper crustal plutons

    NASA Astrophysics Data System (ADS)

    Weis, Philipp; Driesner, Thomas; Scott, Samuel; Lecumberri-Sanchez, Pilar

    2016-04-01

    Heat and mass transport in hydrothermal systems associated with upper crustal magmatic intrusions can result in resources with large economic potential (Kesler, 1994). Active hydrothermal systems can form high-enthalpy geothermal reservoirs with the possibility for renewable energy production. Fossil continental or submarine hydrothermal systems may have formed ore deposits at variable crustal depths, which can be mined near today's surface with an economic profit. In both cases, only the right combination of first-order geologic and hydrologic controls may lead to the formation of a significant resource. To foster exploration for these hydrothermal georesources, we need to improve our understanding of subsurface fluxes of mass and energy by combining numerical process modelling, observations at both active and fossil systems, as well as knowledge of fluid and rock properties and their interactions in natural systems. The presentation will highlight the role of non-linear fluid properties, phase separation, salt precipitation, fluid mixing, permeability structure, hydraulic fracturing and the transition from brittle to ductile rock behavior as major geologic and hydrologic controls on the formation of high-enthalpy and supercritical geothermal resources (Scott et al., 2015), and magmatic-hydrothermal mineral resources, such as porphyry copper, massive sulfide and epithermal gold deposits (Lecumberri-Sanchez et al., 2015; Weis, 2015). References: Kesler, S. E., 1994: Mineral Resources, economics and the environment, New York, McMillan, 391. Lecumberri-Sanchez, P., Steele-MacInnis, M., Weis, P., Driesner, T., Bodnar, R.J. (2015): Salt precipitation in magmatic-hydrothermal systems associated with upper crustal plutons. Geology, v. 43, p. 1063-1066, doi:10.1130/G37163.1 Scott, S., Driesner, T., Weis, P. (2015): Geologic controls on supercritical geothermal resources above magmatic intrusions. Nature Communications, 6:7837 doi: 10.1038/ncomms8837 Weis, P. (2015): The

  5. Origin and interaction of some alkalic and silicic plutons in the Vermilion Granitic Complex, NE Minnesota

    SciTech Connect

    McCall, G.W.; Nabelek, P.I.; Bauer, R.L.; Glascock, M.D.

    1985-01-01

    Alkalic gabbros and tonalites comprise a significant portion of the Archaean crust in the Vermilion Granitic Complex of NE Minnesota. The origin of these and associated rocks has been modeled using major and trace element approaches. Samples of the alkalic gabbro collected from three different intrusions have similar major element, REE, and transition metal concentrations. The REE patterns of these rocks can be modeled as the result of 1% to 3% melting of an undepleted garnet herzolite mantle with REE concentrations three times that of chondrites. However, their Al/sub 2/O/sub 3//CaO ratios of 2 - 3, Sr content of 900-1400 ppm and Ba of 100 - 1600 ppm suggest that the source may have been an enriched, metasomatized mantle. The hornblendites associated with these alkalic rocks have REE patterns which are consistent with crystallization and accumulation from the gabbroic magma. Major and trace element modeling suggest that the granitic dikes which are common throughout the area may be residual liquids formed by 60% crystallization of plagioclase, biotite, hornblende and apatite from the nearby tonalites such as the Burntside of Wakemup Bay plutons. Porphyritic hornblende monzonites composed of centimeter sized hornblende crystals floating in a granitic matrix occur locally. The field relations as well as the major and trace element data are consistent with the formation of these monzonitic rocks by mixing of the granite with partially consolidated hornblendite. These results suggest a complex interaction between alkalic gabbros and tonalites involving fractionation and mixing during the development of the Archaean crust of NE Minnesota.

  6. The origin of rhythmic layering in the Cape Neddick Plutonic Complex, Maine

    SciTech Connect

    Shipley, J. . Dept. of Geology)

    1993-03-01

    The Cape Neddick Plutonic Complex located along the southwestern coast of Maine is a small layered gabbroic body. It contains four concentric gabbros of differing composition, From the center to the exterior these are Cortlandtitic, Anorthositic, Normal, and Pegmatitic gabbros. They vary slightly in the proportion of essential minerals; plagioclase, clinopyroxene, hornblende, and biotite [+-] opaques and olivine. Rhythmic layering is seen in all four gabbros. This layering is also concentric around the center of the complex. The best exposure of the layering is along the coast where non-graded and graded rhythmic layering is seen extensively in the Normal gabbro. Only non-graded layering is seen in the Anorthositic gabbro. Non-graded layers were sampled at two localities. One locality is on Cape Nubble Island in the Normal gabbro. The second locality is in the Anorthositic gabbro along the northern coast. The layers are roughly 5--8 cm in width and are continuous around the complex. They are identified on weathered surfaces as alternating bands of felsic and mafic minerals. Layers are not obvious in hand sample. Approximately 15--20 layers were sampled perpendicular to layering. Petrographic and geochemical studies will help constrain the origin of rhythmic layering in the Cape Neddick Complex. Crystal settling or structural processes seem highly unlikely due to the small distance between the layers and the fact that they are not graded. Possible models include multiple pulses of magma within the same magma chamber, density currents, or in situ fractionation by a nucleation-diffusion process. Modal and chemical analysis of mineral phases within individual layers will allow comparison of the bulk composition of each layer. Analysis of coexisting pyroxene and plagioclase can be used to estimate compositional variations in the parent liquid.

  7. Tectono-magmatic evolution of sheeted plutonic bodies along the north Giudicarie line (northern Italy)

    NASA Astrophysics Data System (ADS)

    Martin, S.; Prosser, G.; Morten, L.

    1993-04-01

    Tectonized slices of foliated quartz-diorite/ quartz-gabbro rocks are exposed along the north Giudicarie line between Dimaro and Rumo (Western Trentino region, north-east Italy). They show geochemical and mineralogical similarities with the north-east corner of the Adamello batholith (Presanella pluton) and may be regarded as a northern apophysis lamella of Adamello. The intrusive bodies were emplaced within the Adria crust at a relatively shallow depth (approximatelyP_{{text{H}}_{text{2}} {text{O}}} equal to 3 kbar) along a proto-Giudicarie line under transtensive conditions during late Oligocene. Only near Rumo has contact metamorphism on the Austroalpine basement been observed, whereas in other outcrops it has been tectonically removed by later movements along the Giudicarie line. In the Samoclevo lamella a magmatic flow texture, which developed during the emplacement of a crystal mush at shallow depth, is recorded by the preferred alignment of plagioclase and hornblende. A solid state foliation, outlined by quartz crystal aggregates, green hornblende and biotite, has been observed mostly in the Rumo lamella. This indicates that a later ductile deformation, which developed under decreasing temperatures, overprinted the intrusive rocks. This deformation probably reflects late Oligocene strike-slip movements along the Tonale and Giudicarie lines. Finally semi-brittle to brittle deformation overprints the foliated igneous lamellae producing cataclasites and pseudotachylites. Sometimes these structures are subsequently cut by prehnite and epidote bearing veins. During this event, the intrusive lamellae were decoupled from their contact aureole and carried over the Insubric Flysch of the southern Alps. This last tectonic phase may be correlated to the Upper Miocene neo-Alpine transpressive event along the Giudicarie Line.

  8. Mapping brittle fracture zones in three dimensions: high resolution traveltime seismic tomography in a granitic pluton

    NASA Astrophysics Data System (ADS)

    Martí, D.; Carbonell, R.; Tryggvason, A.; Escuder, J.; Pérez-Estaún, A.

    2002-04-01

    Fractured and altered zones within a granitic pluton are mapped in three dimensions by means of high resolution seismic traveltime tomography. The input traveltimes were picked from offset and azimuth variable vertical seismic profiles (OVSP) acquired in three boreholes and from seismic shot gathers of four CDP high resolution seismic reflection profiles recorded on the surface. For the OVSP data a hydrophone streamer placed in the boreholes recorded the acoustic energy generated (a signal with a frequency content between 15 to 150 Hz) by a Vibroseis truck at source points distributed every 30 m in a rectangular grid of 620 m by 150 m. The combination of borehole and surface seismic data resulted in an increase in the ray density of the shallow subsurface. The tomographic algorithm uses a variable model grid, with a finer grid spacing close to the surface were ray density is highest and the velocity variations are strongest. Therefore the resulting velocity models feature more detail at shallow levels. A simple and smooth starting velocity model was derived from P -wave velocity logs. Careful surface geological mapping, and borehole geophysical data, P - and S -wave velocity logs and Poisson's ratio depth functions, provided key constraints for a physically reasonable 3-D interpretation of the tomograms. The low velocity anomalies constrained by the tomographic images were interpreted as unconsolidated rock, fractures and altered zones which correlate with structures mapped at the surface or velocity anomalies identified in the logs. Subsequent resolution analysis revealed that the derived velocity model is well constrained to depths of 60 m.

  9. Petrological and geochemical constraints on granitoid formation: The Waldoboro Pluton Complex, Maine

    SciTech Connect

    Barton, M. . Dept. of Geological Science); Sidle, W.S. )

    1992-01-01

    The Waldoboro Pluton Complex (WPC) comprises seven units ranging from qtz-diorite to aplite. The country rocks are biotite-rich metagraywackes with minor shales mostly belonging to the Proterozoic Z-Ordovician Bucksport Formation. Field evidence strongly suggests that the WPC formed in-situ: contacts with the country rock are cryptic, transitional and concordant; restitic minerals in the granitoids are identical to those in the country rocks; prolific metasedimentary enclaves in the WPC are locally derived. Major and trace element data for country rock and the most voluminous units of the WPC define consistent linear trends suggesting limited melt segregation and retention of a high proportion of restite. Mixing models and partial melting models require 54--76% melting for generation of the gneissic granites and two-mica granites. Garnet-biotite geothermometry and garnet-Al[sub 2]SiO[sub 5]-SiO[sub 2]-plagioclase geobarometry indicate that the WPC formed at T = 740--780 C and P = 0.4--0.7 GPa. Published experimental data show that < 50% melting is likely under these conditions if melting is controlled by dehydration reactions. Bucksport lithologies contain < 20% biotite, suggesting that the maximum amount of melt that could have formed by dehydration melting is < 20%, even if all biotite was consumed during melting. It seems probable that a free fluid phase was required to generate the WPC. Migmatization is apparent in all lithologies (including amphibolites) in the vicinity of the WPC, consistent with fluid-present melting. Fluid may have ingressed along the St. George thrust, but the source of the fluid is unknown.

  10. Geochemistry, zircon U-Pb ages and Sr-Nd-Hf isotopes of an Ordovician appinitic pluton in the East Kunlun orogen: New evidence for Proto-Tethyan subduction

    NASA Astrophysics Data System (ADS)

    Xiong, Fuhao; Ma, Changqian; Wu, Liang; Jiang, Hong'an; Liu, Bin

    2015-11-01

    Appinite is commonly derived from a mantle source in subduction zones and thus holds a key to constrain the tectonic evolution of ancient orogens. This study presents chronological, mineralogical and geochemical data for one appinitic pluton from the south Tethyan suture zone in the East Kunlun orogen, Northern Tibetan Plateau. The pluton is predominantly composed of hornblende-rich mafic appinites, with minor amounts of granodiorite. Zircon U-Pb age of the granodiorite (466 Ma) is identical to the mafic appinites (447-450 Ma). The mafic appinites are commonly hornblende diorites, which comprise large amounts of magnesio-hornblende [Mg/(Fe + Mg) = 0.61-0.68] and andesine (An43-54). The hornblende diorites have low contents of SiO2 (48.62-54.95 wt.%), high contents of total FeO (7.90-12.84 wt.%) and MgO (4.32-11.89 wt.%) and moderate values of Mg# [Mg# = molar 100 ∗ Mg/(Mg + Fe); 49-69]. Their geochemistry displays: slight enrichment of light rare earth elements ((La/Yb)N = 1.89-6.84) and flat heavy rare earth elements ((Ga/Yb)N = 1.49-2.22); enrichment in large ion lithophile elements and depletion in high field strength elements; less-enriched isotopic compositions with initial 87Sr/86Sr ratios of 0.70536-0.70617, εNd(t) of 0.79-3.02 and zircon εHf(t) of 8.73-12.82. The associated granodiorites comprise plagioclase (45-50 vol.%, An = 26-39), quartz (15-20 vol.%), K-feldspar (5-10 vol.%), ferrohornblende [2-5 vol.%, (Mg/(Fe + Mg) = 0.45-0.49] and epidote (1-5 vol.%). The epidotes have pistacite components ranging from 23 to 28. The granodiorites exhibit calc-alkaline character, and have rare earth and trace element patterns similar to the hornblende diorites. The geochemical compositions and simulations suggest that the parental magma of the mafic appinites was generated by partial melting of one depleted mantle source which was metasomatised by subducted sediment-derived felsic melts (ca. 20-25%). Fractional crystallization of clinopyroxene, hornblende

  11. FINAL REPORT. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Investigation of behavior of actinides in alkaline media containing Al(III) showed that no aluminate complexes of actinides in oxidation states (III-VII) were formed in alkaline solutions. At alkaline precipitation (pH 10-14) of actinides in presence of Al(III) formation of alumi...

  12. Deformation within the cannibal creek pluton and its aureole, Queensland, Australia: a re-evaluation of ballooning as an emplacement mechanism

    NASA Astrophysics Data System (ADS)

    Godin, Paul

    1994-05-01

    Structures within the foliated Cannibal Creek granite and its deformed aureole indicate that the pluton appears to have been emplaced after a minimum of two strong regional deformation events ( D1, D2), that contact metamorphic porphyroblast growth began during the early stages of a third aureole-centred event ( Da) and that a fourth weak deformation overprints all earlier structures, at least within the strain-softened aureole. The aureole deformation ( Da) is most strongly developed at the pluton contact, decreasing in intensity both inwards to the core, and outwards into the wall rock. Earlier interpretations linking ( Da) strain to expansion (ballooning) of the pluton during emplacement are no longer favoured. Previously discussed diagnostic criteria of ballooning, such as closed elliptical trend lines for the aureole foliation, and new field evidence, such as radial magmatic lineations and moderate to high-temperature solid-state deformation of external sheath dykes, are either ambiguous or point strongly toward syn- to pre-tectonic emplacement of a piercement diapir. Less than 30% of the pluton volume appears to have been accommodated by wall rock shortening as the result of ballooning or diapiric ascent. The rest was likely accommodated by a combination of broad wavelength regional doming (1-5 mm year -1) above the pluton, far field redistribution of mass into the source area plus or minus some component of diapiric backflow, stoping, assimilation and dilation in fault bends or fold hinges.

  13. Geological and petrological aspects of Ni-Cu-PGE mineralization in the early Paleoproterozoic Monchegorsk layered mafic-ultramafic complex, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Sharkov, E. V.; Chistyakov, A. V.

    2014-05-01

    The Early Paleoproterozoic Monchegorsk Complex comprises two independent large layered mafic-ultramafic intrusions: the Monchegorsk pluton and the Main Range massif formed about 2.50 and 2.46 Ga ago, respectively. They are composed of similar cumulates, though they differ somewhat in the isotopic parameters of rocks, cumulate stratigraphy and derived from siliceous high-Mg series melts that arose in the same large long-living volcanic center. The economic syngenetic Ni-Cu-PGE sulfide mineralization related to the earlier Monchegorsk pluton is represented by two types of ores. The first type, pertaining to fractionation of the primary melt, is opposite to the reef formed due to injection of a special ore-bearing melt into the solidifying intrusive chamber. The primary magmatic mineralization is largely composed of Ni-Fe-Cu sulfides and Pd-Pt sulfides, bismuthides, and tellurides. Only small PGE and probably chromite occurrences are related to the Main Range massif. In the Mid-Paleoproterozoic (2.0-1.9 Ga), the complex was transformed into a collage of tectonic blocks confined to the regional fault zone. The Monchegorsk pluton was retained better, and only rocks of its southern framework were involved into tectonic and metamorphic reworking with the formation of economic metamorphic low-sulfide PGE mineralization with widespread Pd and Pt telluro-bismuthides, arsenides, stannides, antimonides, and selenides. The ore formation was accompanied by PGE redistribution and segregation of lenticular orebodies with diffuse contours. Thus, the Monchegorsk ore cluster is characterized by juxtaposition of unaltered primary magmatic deposits and those formed as a result of their metamorphism and distinguished from the former by structure and composition. The comparative study of these deposits opens up new possibilities for comprehending ore-forming processes in the same situations.

  14. Constraints on ages of Taconian and Acadian deformation from zircon evaporation ages of felsic plutons from western Massachusetts

    SciTech Connect

    Williamson, B.F.; Karabinos, P. . Dept. of Geology)

    1993-03-01

    New dates on three felsic plutons constrain the age of Taconian and Acadian deformation in western Massachusetts. The tonalitic Hallockville Pond Gneiss intrudes the Moretown Formation of the Rowe-Hawley belt and shows deformation comparable in degree and orientation to that of the surrounding rocks. The Middlefield Granite, a quartz monzonite, intrudes the Rowe and Moretown Formations at their contact. The Williamsburg Granodiorite, of minimum-melt composition, intrudes Silurian and Devonian formations of the Connecticut Valley Synclinorium, east of the Row-Hawley belt, and contains no obvious deformation fabric. [sup 207]Pb/[sup 206]Pb single-grain zircon evaporation ages for these plutons are as follows: the Hallockville Pond Gneiss, 484 [plus minus] 7 Ma; the Middlefield Granite, 447 [plus minus] 3 Ma (weighted average of 4 grains); and the Williamsburg Granodiorite, 373 [plus minus] 5 Ma (weighted average of 3 grains). The Moretown Formation, presently correlated with the Middle Ordovician Beauceville Formation in Quebec, must be older than 484 Ma (Early Ordovician), the age of the intruding Hallockville Pond Gneiss, which might be related to rocks in the proposed Shelburne Falls arc of similar age (Karabinos and Tucker, 1992). Field relations and the age of the Middlefield Granite show that if the Rowe-Moretown contact is a fault, one interpretation suggested by Stanley and Hatch (1988) and advocated by Ratcliffe et al. (1992), then Taconian thrusting in this area ended by 447 Ma because the pluton is not offset by faults. The 373 Ma age of the unfoliated Williamsburg Granodiorite, together with a U-Pb zircon age on a strongly deformed sill in the Granville dome of 376 [plus minus] 4 Ma, tightly constrains the timing of the main phase of Acadian deformation in western Massachusetts.

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

    PubMed

    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 ord