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| Titel |
Morphology of the pore space in claystones – evidence from BIB/FIB ion beam sectioning and cryo-SEM observations |
| VerfasserIn |
G. Desbois, J. L. Urai, P. A. Kukla |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1815-381X
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| Digitales Dokument |
URL |
| Erschienen |
In: eEarth ; 4, no. 1 ; Nr. 4, no. 1 (2009-07-08), S.15-22 |
| Datensatznummer |
250001539
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| Publikation (Nr.) |
 copernicus.org/ee-4-15-2009.pdf |
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| Zusammenfassung |
| The morphology of pore space has a strong effect on mechanical and transport
properties of mudrocks and clay-rich fault gouge, but its characterization
has been mostly indirect. We report on a study of Boom clay from a proposed
disposal site of radioactive waste (Mol site, Belgium) using high resolution
SEM at cryogenic temperature, with ion beam cross-sectioning to prepare
smooth, damage free surfaces. Pores commonly have crack-like tips, preferred
orientation parallel to bedding and power law size distribution. We define a
number of pore types depending on shape and location in the microstructure:
large jagged pores in strain shadows of clastic grains, high aspect ratio
pores between similarly oriented phyllosilicate grains and crescent-shaped
pores in saddle reefs of folded phyllosilicates. 3-D reconstruction by
serial cross-sectioning shows 3-D connectivity of the pore space. These
findings offer a new insight into the morphology of pores down to nano-scale
in comparison to traditional pore size distributions calculated from mercury
Injection experiments, explain slaking of clays by successive wetting and
drying and provide the basis for microstructure-based models of transport in
clays. |
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