Results 311 to 320 of about 26,623 (334)

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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Tunneling radiative recombination in K-feldspar sanidine

Nuclear Tracks and Radiation Measurements, 1993
Abstract A study has been made of the afterglow from three sanidine samples following beta irradiation. The temperature was lowered to 77 K, then raised to 750 K and the emission spectra were measured from ultraviolet (u.v.) to 890 nm. An intense emission is observed at liquid nitrogen temperature, entirely in the red and infrared (i.r.) part of the ...
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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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Optical dating: K-feldspars optical response stimulation spectra

Quaternary Science Reviews, 1988
Abstract K-feldspars were exposed to optical stimulation using different wavelengths and the resulting emissions studied. The existence of a rather deep light-sensitive trap (∼2eV) is shown. The contents of this trap may be bleached by both the visible (490 nm) and infrared light region (860 nm, 930 nm).
G. Hütt, I. Jaek, J. Tchonka
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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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Lead-isotope inhomogeneity in Precambrian igneous K-feldspars

Geochimica et Cosmochimica Acta, 1977
Stepwise Pb-removal experiments, using both vacuum volatilization and HF-leaching techniques, on acid-washed K-feldspar concentrates from Precambrian igneous rocks show that all contain some unsupported radiogenic Pb. Two types of radiogenic Pb were recognized. One has a “normal” isotopic composition, with relative abundances of ^(206)Pb, ^(207)Pb and ^
Ludwig, Kenneth R., Silver, Leon T.
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K-Feldspar Cement in the Jacobsville Sandstone

SEPM 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% Na2O and
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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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Hydrothermal synthesis of nano-kaolinite from K-feldspar

Ceramics International, 2018
Abstract Development of sustainable routes for the synthesis of kaolinite in nano-scale (nano-kaolinite) is very significant for producing high quality kaolinite of paper-coating grade in kaolin industry. Duplicating chemical weathering processes in nature, two routes were developed and compared for the synthesis of nano-kaolinite from K-feldspar ...
Jiangyan Yuan, Jing Yang, Hongwen Ma, Shuangqing Su, Qianqian Chang, Sridhar Komarneni   +5 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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