ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Stable isotopes as tracers of metamorphic processes: introduction (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of metamorphic geology 12 (1994), S. 0 
    Details
    ISSN: 1525-1314
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1525-1314.1994.tb00016.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Controls on the mechanisms of fluid infiltration and front advection during regional metamorphism: a stable isotope and textural study of retrograde Dalradian rocks of the SW Scottish Highlands (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of metamorphic geology 12 (1994), S. 0 
    Details
    ISSN: 1525-1314
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Vein-controlled retrograde infiltration of H2O-CO2 fluids into Dalradian epidote amphibolite facies rocks of the SW Scottish Highlands under greenschist facies conditions resulted in alteration of calcite-rich marble bands to dolomite and spatially associated 18O enrichment of about 10%. on a scale of metres. Fluid inclusion data indicate that the retrograde fluid was an H2O-salt mixture with a low CO2 content, and that the temperature of the fluid was about 400d̀ C. Detailed petrographic and textural (backscattered electron imaging) studies at one garnet-grade locality show that advection of fluid into marbles proceeded by a calcite-calcite grain edge flow mechanism, while alteration of non-carbonate wall-rock is associated with veinlets and microcracks.Stable isotopic analysis of carbonates from marble bands provides evidence for advection of isotopic fronts through carbonate wall-rocks perpendicular to dolomite veins, and fluid fluxes in the range 2.4–28.6 m3/m2 have been computed from measured advection distances. Coincidence of isotope and reaction fronts is considered to result from reaction-enhanced kinetics of isotope exchange at the reaction front. Front advection distances are related to the proportion of calcite to quartz in each marble band, with the largest advection distance occurring in nearly pure calcite matrix. This relationship indicates that fluid flow in carbonates is only possible along fluid-calcite-calcite grain edges. However, experimental constraints on dihedral angles in calcite-fluid systems require that pervasive infiltration occurred in response to calcite dissolution initiated at calcite-calcite grain junctions rather than to an open calcite pore geometry.The regional extent of the retrograde infiltration event has been documented from the high δ18O of dolomite-ankerite carbonates from veins and host-rocks over an area of least 50 × 50 km in the SW Scottish Highlands. Isotopically exotic 18O-rich retrograde fluids have moved rapidly upwards through the crust, inducing isotopic exchange and mineral reaction in wall-rocks only where lithology, pore geometry or mineral solubilities, pressure and temperature have been appropriate for pervasive infiltration to occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1525-1314.1994.tb00020.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The effect of hydrogen on oxygen diffusion in quartz: evidence for fast proton transients? (1988)
    [s.l.] : Nature Publishing Group
    Nature 335 (1988), S. 243-245 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Water enhances mineral reactivity through solution-reprecipi-tation processes1, greatly increases Al/Si interdiffusion rates in feldspars2"4, influences the conductivity of quartz5, and causes dramatic 'hydrolytic' weakening of quartz in deformation experiments and in nature6'7. Oxygen diffusion in ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/335243a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    P-T-X effects on equilibrium carbonate-H2O-CO2-NaCl dihedral angles: constraints on carbonate permeability and the role of deformation during fluid infiltration (1995)
    Springer
    Contributions to mineralogy and petrology 119 (1995), S. 301-313 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Fluid-solid-solid dihedral angles in the NaCl-H2O-CO2-calcite-dolomite-magnesite system have been determined at pressures ranging from 0.5 to 7 kbar and temperatures from 450°C to 750°C. At 1 kbar and 650°C, both dolomite and magnesite exhibit a dihedral angle minimum for intermediate H2O-CO2 fluids similar to that previously determined by the present authors for calcite, but the depth of the minimum is smaller, being above the critical value of 60° for both dolomite and magnesite for all fluid compositions. Calcite-calcite-brine dihedral angles at 650°C have been determined in the pressure range 1–5 kbar. Angles decrease with increasing salt content of the fluid, tending towards a constant value of about 65° for strong brines at pressures above 2 kbar. There is a general increase of angle with increasing pressure which is most marked for strong brines. A positive correlation of angle with pressure is also observed in calcite-H2O-CO2 fluids, the position of the minimum moving towards higher angles and towards H2O-rich fluids with increasing pressure. The permeability window previously observed by the present authors at 1 kbar and intermediate fluid compositions closes at about 1.5 kbar. The results demonstrate that the permeability of carbonates to grain edge fluid flow is only possible at low pressures and for fluids of restricted H2O-CO2-NaCl compositions. However, geochemical evidence from metamorphic terrains suggests that pervasive infiltration does occur under conditions where impermeability is predicted. From examination of published studies of infiltrated carbonates we conclude that deformation plays a critical role in enhancing carbonate permeability. Possible mechanisms for this include shear-enhanced dilatancy (micro-cracking), fluid inclusion drag by deformation-controlled grain boundary migration, and dynamically maintained transient grain boundary fluid films.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004100050044
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The correlation of reaction and isotope fronts and the mechanism of metamorphic fluid flow (2000)
    Springer
    Contributions to mineralogy and petrology 138 (2000), S. 364-375 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Infiltration of a metabasite sill from Islay, Scotland by an H2O-CO2 fluid caused (1) modification of δ18O and (2) carbonation at the sill margins. Maps of δ18O and reaction progress were constructed from a 20 × 47.7 metre sample grid across the sill. The grid consisted of 300 samples, spaced at m, dm and cm intervals, many of which were analysed for both δ18O and reaction progress. The δ18O was determined by laser fluorination of whole rock silicate powders and reaction progress was determined by rapid field-based measurement of % calcite (“fizz-o-meter”, Skelton et al. 1995). Reaction and isotope fronts outlined tube-like features that emanate from the sill margin and discrete nodes that, although detached from the sill margin in two dimensions, are thought to represent sections through similar tubes in three dimensions. We envisage that these protrusions are the fossil record of metamorphic “fluid pathways” whereby fluid permeated the sill. Isotope and reaction fronts are found to correlate spatially as predicted by a modified form of the chromatographic equation which describes this envisaged geometry, that is where isotopic and reactive transport in the fluid phase are facilitated by advection along specific fluid pathways and transverse diffusion in the surrounding rock. These fluid pathways consist of bundles of anastomosing grain boundary channels or micro-cracks, which are thought to propagate through transient cyclic infiltration, reaction, porosity enhancement and fracturing. This mechanism is self-perpetuating and accentuates random perturbations at the sill margin to form the observed tubes. We argue that this is the earliest stage of the infiltration process which has affected metabasites of the SW Scottish Highlands and that subsequent shear deformation of the reacted rims of these pathways, has caused their re-orientation and juxtaposition to form the reacted sill margins described by Skelton et al. (1995).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004100050569
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    An experimental study of the diffusion of oxygen in quartz and albite using an overgrowth technique (1986)
    Springer
    Contributions to mineralogy and petrology 92 (1986), S. 322-330 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Diffusion rates of18O tracer in quartz (∥ c, 1 Kb H2O) and Amelia albite (⊥ 001, 2 Kb H2O) have been measured, using Secondary Ion Mass Spectrometry (SIMS). A new technique involving hydrothermal deposition of labelled materials has removed the possibility of pressure solution-reprecipitation processes adversely affecting the experiments. Reported diffusion constants are:β-quartz (∥ c), $$D_0 = 3.4\left( {\begin{array}{*{20}c} { + 4.8} \\ { - 2.0} \\ \end{array} } \right)x 10^{ - {\text{13}}} {\text{m}}^{\text{2}} {\text{s}}^{ - {\text{1}}} $$ ,Q=98±7 KJ mol−1 (600–825° C, 1 Kb); Amelia albite (⊥ 001), $$D_0 = 1.0\left( {\begin{array}{*{20}c} { + 2.0} \\ { - 0.7} \\ \end{array} } \right)x 10^{ - {\text{13}}} {\text{m}}^{\text{2}} {\text{s}}^{ - {\text{1}}} $$ ,Q=85±7 KJ mol−1, (400–600° C, 2 Kb). Measured quartz18O diffusivities decrease discontinuously at theα-β transition, reflecting strong structural influences. The reported albite data agree with previously recorded studies, butβ-quartz data indicate significantly lower activation energies. Possible causes of this discrepancy, and some geological consequences, are noted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00572161
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Reply to comments “On the kinetics of textural equilibrium in forsterite marbles” by M.B. Holness, M.J. Bickle and C.M. Graham (1992)
    Springer
    Contributions to mineralogy and petrology 111 (1992), S. 421-422 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00311202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    P-T-X effects on equilibrium carbonate-H2O-CO2-NaCl dihedral angles: constraints on carbonate permeability and the role of deformation during fluid infiltration (1995)
    Springer
    Contributions to mineralogy and petrology 119 (1995), S. 301-313 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Fluid-solid-solid dihedral angles in the NaCl-H2O-CO2-calcite-dolomite-magnesite system have been determined at pressures ranging from 0.5 to 7 kbar and temperatures from 450°C to 750°C. At 1 kbar and 650°C, both dolomite and magnesite exhibit a dihedral angle minimum for intermediate H2O-CO2 fluids similar to that previously determined by the present authors for calcite, but the depth of the minimum is smaller, being above the critical value of 60° for both dolomite and magnesite for all fluid compositions. Calcite-calcite-brine dihedral angles at 650°C have been determined in the pressure range 1–5 kbar. Angles decrease with increasing salt content of the fluid, tending towards a constant value of about 65° for strong brines at pressures above 2 kbar. There is a general increase of angle with increasing pressure which is most marked for strong brines. A positive correlation of angle with pressure is also observed in calcite-H2O-CO2 fluids, the position of the minimum moving towards higher angles and towards H2O-rich fluids with increasing pressure. The permeability window previously observed by the present authors at 1 kbar and intermediate fluid compositions closes at about 1.5 kbar. The results demonstrate that the permeability of carbonates to grain edge fluid flow is only possible at low pressures and for fluids of restricted H2O-CO2-NaCl compositions. However, geochemical evidence from metamorphic terrains suggests that pervasive infiltration does occur under conditions where impermeability is predicted. From examination of published studies of infiltrated carbonates we conclude that deformation plays a critical role in enhancing carbonate permeability. Possible mechanisms for this include shear-enhanced dilatancy (micro-cracking), fluid inclusion drag by deformation-controlled grain boundary migration, and dynamically maintained transient grain boundary fluid films.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307289
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Melting of albite and dehydration of brucite in H2O–NaCl fluids to 9 kbars and 700–900°C: implications for partial melting and water activities during high pressure metamorphism (1996)
    Springer
    Contributions to mineralogy and petrology 124 (1996), S. 370-382 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  The melting reaction: albite(solid)+ H2O(fluid) =albite-H2O(melt) has been determined in the presence of H2O–NaCl fluids at 5 and 9.2 kbar, and results compared with those obtained in presence of H2O–CO2 fluids. To a good approximation, albite melts congruently at 9 kbar, indicating that the melting temperature at constant pressure is principally determined by water activity. At 5 kbar, the temperature (T)- mole fraction (X (H2O) ) melting relations in the two systems are almost coincident. By contrast, H2O–NaCl mixing at 9 kbar is quite non-ideal; albite melts ∼70 °C higher in H2O–NaCl brines than in H2O–CO2 fluids for X (H2O) =0.8 and ∼100 °C higher for X (H2O) =0.5. The melting temperature of albite in H2O–NaCl fluids of X (H2O)=0.8 is ∼100 °C higher than in pure water. The P–T curves for albite melting at constant H2O–NaCl show a temperature minimum at about 5 kbar. Water activities in H2O–NaCl fluids calculated from these results, from new experimental data on the dehydration of brucite in presence of H2O–NaCl fluid at 9 kbar, and from previously published experimental data, indicate a large decrease with increasing fluid pressure at pressures up to 10 kbar. Aqueous brines with dissolved chloride salt contents comparable to those of real crustal fluids provide a mechanism for reducing water activities, buffering and limiting crustal melting, and generating anhydrous mineral assemblages during deep crustal metamorphism in the granulite facies and in subduction-related metamorphism. Low water activity in high pressure-temperature metamorphic mineral assemblages is not necessarily a criterion of fluid absence or melting, but may be due to the presence of low a (H2O) brines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004100050197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization (2014)
    Springer Nature
    Details
    Publication Date: 2014-06-22
    Print ISSN: 1061-4036
    Electronic ISSN: 1546-1718
    Topics: Biology , Medicine
    Published by Springer Nature
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...