Results 221 to 230 of about 7,058,324 (263)

A study of strontium diffusion in K-feldspar, Na-K feldspar and anorthite using Rutherford Backscattering Spectroscopy

Earth and Planetary Science Letters, 1992
Abstract Sr chemical diffusion has been measured in orthoclase, anorthoclase and anorthite under dry, 1-atm conditions. A strontium oxide-aluminosilicate powder mixture was used as the source material, with Rutherford Backscattering Spectroscopy (RBS) used to measure diffusion profiles.
D.J. Cherniak, E.B. Watson
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The optical bleaching of thermoluminescence in K-feldspar

Journal of Physics D: Applied Physics, 2001
The thermoluminescence (TL) of K-feldspar extracted from sediment was bleached by means of a sunlight simulator. The differences in the TL bleaching efficiency of different trap groups are correlated with significant differences between trap parameters.
A Chruscinska, H L Oczkowski, K R Przegietka   +2 more
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Planar defects and dissociation of dislocations in a K feldspar

Philosophical Magazine A, 1987
We investigate some slip systems active in sanidine, the high-temperature form of K feldspar (KAlSi3O8) by atomistic computer modelling of possible dislocation and planar defect structures. As a first approximation, we assume that the disordered Al-SiO2 network behaves as a purely covalent SiO2 network, allowing the use of a Keating-like potential ...
Heggie, MI, Zheng, Y
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Experimental deformation of K-feldspar single crystals

Bulletin de Minéralogie, 1979
Sanidine single crystals have been deformed in order to study the possible slip systems in this mineral. Runs have been performed at 700, 900 and 1,1000° C, with a confining pressure of 16 kbâr at a strain rate of 2 x 10-6 s-1 for 11 different crystallographic orientations.
Willaime, Christian, Christie, John, Kovacs, Marie-Paule   +2 more
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Natural luminescence and anomalous fading in K-feldspar

Radiation Measurements, 2012
This study investigated the relationship between the natural luminescence intensity, the amplitude of anomalous fading and the apparent IRSL age of a suite of feldspar single grains. Correlating natural luminescence with fading may simplify the identification of weakly to non-fading feldspars grains in sediments.
Michel Lamothe, Magali Barré, Sébastien Huot, Stéphanie Ouimet   +3 more
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Thermodynamic mixing properties of Rb-K feldspars

American Mineralogist, 2008
Hydrofluoric acid solution calorimetric measurements conducted at 50 °C on a series of Al-Si ordered Rb-K feldspars reveal that the enthalpies Rb-K mixing ( H ex ) for this series are positive, with maximum values skewed toward Rb-rich compositions. However, the magnitudes of H ex are greatly reduced relative to those for Na-K feldspars, as are the
G. L. Hovis, J. Roux
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The fractional thermoluminescence of bleached K-feldspars

Journal of Luminescence, 2001
The fractional glow technique was applied for the investigation of trap occupation in optically bleached K-feldspars separated from sediments. Various bleaching times and two spectra ranges of sunlight simulator were used. Four trap groups exhibit different sensitivities to the bleaching.
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Alkali ion migration in albite and K-feldspar

Physics and Chemistry of Minerals, 2004
As part of a study of ion migration mechanisms in feldspars, the dynamical behaviour of the alkali metal cations ions in albite and K-feldspar has been investigated using a combination of dielectric spectroscopy and atomistic computer simulation techniques.
A. Jones, D. Palmer, M. S. Islam, M. Mortimer   +3 more
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In vacuo crushing experiments and K-feldspar thermochronometry

Earth and Planetary Science Letters, 1993
Using in c, acuo crushing methods, both C1- and K-correlated components of trapped 4°At have recently been identified in hypersolvus alkali feldspar and K-feldspar-bearing 'chert' and stromatolite samples. If these components re-emerge during the late stages of thermal degassing, interpretation of 4°Ar/39Ar age spectra could be complicated.
T. Mark Harrison, Matthew T. Heizler, Oscar M. Lovera   +2 more
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K-feldspar cement in the Jacobsville Sandstone

Journal of Sedimentary Research, 1978
Abstract Authigenic, monoclinic, potassium feldspar has been found in the Jacobsville sandstone. The feldspar is chert-like in appearance or recrystallized in an adularia habit. It contains < 0.1% Na 2 O and <<0.1% CaO.
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