4D porosity evolution during pressure-solution of NaCl in the presence of phyllosilicates

Macente, A. , Fusseis, F., Butler, I. B., Tudisco, E., Hall, S. A. and Andò, E. (2018) 4D porosity evolution during pressure-solution of NaCl in the presence of phyllosilicates. Earth and Planetary Science Letters, 502, pp. 115-125. (doi:10.1016/j.epsl.2018.08.032)

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Abstract

Pressure-solution creep is one of the most common crustal deformation mechanisms, inducing changes in the porosity and permeability of rocks. For a variety of rock types undergoing pressure solution, it has been shown that the presence of phyllosilicates may significantly enhance the rate of the pressure-solution process. In this experimental investigation, we present 4-dimensional (three dimensions + time) X-ray microtomographic data that contrast deformation by pressure-solution of a pure NaCl aggregate with that of a mixture of NaCl and biotite. The results show that for mixed samples (NaCl+biotite), phyllosilicates induce a marked reduction in porosity and pore connectivity and contribute to an increase in the local strain rates by an order of magnitude over pure NaCl samples. At the same time, phyllosilicates do not induce strain localization in the sample. We discuss various possible explanations for these observations including a possible positive feedback between the porosity distribution and pressure solution. Our study yields novel insights into the local effects of phyllosilicates during pressure-solution creep and provides full 4-dimensional imaging and characterization of the coupled evolution of porosity and pore connectivity over previously unprecedented experimental time scales.

Item Type:Articles
Additional Information:The work was supported by the PhD studentship funding from the School of Geosciences, University of Edinburgh.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Macente, Dr Alice
Authors: Macente, A., Fusseis, F., Butler, I. B., Tudisco, E., Hall, S. A., and Andò, E.
College/School:College of Science and Engineering > School of Geographical and Earth Sciences
Journal Name:Earth and Planetary Science Letters
Publisher:Elsevier
ISSN:0012-821X
ISSN (Online):1385-013X
Published Online:13 September 2018
Copyright Holders:Copyright © 2018 Elsevier B.V.
First Published:First published in Earth and Planetary Science Letters 502: 115-125
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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