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Subseismic to Seismic Slip in Smectite Clay Nanofoliation

Smectite clays are the main constituent of slipping zones found in subduction zone faults at shallow depth (e.g., <1‐km depth in the Japan Trench) and in the decollements of large landslides (e.g., 1963 landslide, Vajont, Italy). Therefore, deformation processes in smectite clays may control the...

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Autores principales: Aretusini, S., Plümper, O., Spagnuolo, E., Di Toro, G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6919425/
https://www.ncbi.nlm.nih.gov/pubmed/31894196
http://dx.doi.org/10.1029/2019JB017364
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author Aretusini, S.
Plümper, O.
Spagnuolo, E.
Di Toro, G.
author_facet Aretusini, S.
Plümper, O.
Spagnuolo, E.
Di Toro, G.
author_sort Aretusini, S.
collection PubMed
description Smectite clays are the main constituent of slipping zones found in subduction zone faults at shallow depth (e.g., <1‐km depth in the Japan Trench) and in the decollements of large landslides (e.g., 1963 landslide, Vajont, Italy). Therefore, deformation processes in smectite clays may control the mechanical behavior from slow creep to fast accelerations and slip during earthquakes and landslides. Here, we use (1) laboratory experiments to investigate the mechanical behavior of partly water‐saturated smectite‐rich gouges sheared from subseismic to seismic slip rates V and (2) nanoscale microscopy to study the gouge fabric. At all slip rates, deformation localizes in volumes of the gouge layer that contain a “nanofoliation” consisting of anastomosing smectite crystals. “Seismic” nanofoliations produced at V = 0.01, 0.1, and 1.3 m/s are similar to “subseismic” nanofoliations obtained at V = 10(−5) m/s. This similarity suggests that frictional slip along water‐lubricated smectite grain boundaries and basal planes may occur from subseismic to seismic slip rates in natural smectite‐rich faults. Thus, if water is available along smectite grain boundaries and basal planes, nanofoliations can develop from slow to fast slip rates. Still, when nanofoliations are found highly localized in a volume, they can be diagnostic of slip that occurred at rates equal or larger than 0.01 m/s. In such a case, they could be markers of past seismic events when found in natural fault rocks.
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spelling pubmed-69194252019-12-30 Subseismic to Seismic Slip in Smectite Clay Nanofoliation Aretusini, S. Plümper, O. Spagnuolo, E. Di Toro, G. J Geophys Res Solid Earth Research Articles Smectite clays are the main constituent of slipping zones found in subduction zone faults at shallow depth (e.g., <1‐km depth in the Japan Trench) and in the decollements of large landslides (e.g., 1963 landslide, Vajont, Italy). Therefore, deformation processes in smectite clays may control the mechanical behavior from slow creep to fast accelerations and slip during earthquakes and landslides. Here, we use (1) laboratory experiments to investigate the mechanical behavior of partly water‐saturated smectite‐rich gouges sheared from subseismic to seismic slip rates V and (2) nanoscale microscopy to study the gouge fabric. At all slip rates, deformation localizes in volumes of the gouge layer that contain a “nanofoliation” consisting of anastomosing smectite crystals. “Seismic” nanofoliations produced at V = 0.01, 0.1, and 1.3 m/s are similar to “subseismic” nanofoliations obtained at V = 10(−5) m/s. This similarity suggests that frictional slip along water‐lubricated smectite grain boundaries and basal planes may occur from subseismic to seismic slip rates in natural smectite‐rich faults. Thus, if water is available along smectite grain boundaries and basal planes, nanofoliations can develop from slow to fast slip rates. Still, when nanofoliations are found highly localized in a volume, they can be diagnostic of slip that occurred at rates equal or larger than 0.01 m/s. In such a case, they could be markers of past seismic events when found in natural fault rocks. John Wiley and Sons Inc. 2019-07-29 2019-07 /pmc/articles/PMC6919425/ /pubmed/31894196 http://dx.doi.org/10.1029/2019JB017364 Text en © 2019. The Authors. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Aretusini, S.
Plümper, O.
Spagnuolo, E.
Di Toro, G.
Subseismic to Seismic Slip in Smectite Clay Nanofoliation
title Subseismic to Seismic Slip in Smectite Clay Nanofoliation
title_full Subseismic to Seismic Slip in Smectite Clay Nanofoliation
title_fullStr Subseismic to Seismic Slip in Smectite Clay Nanofoliation
title_full_unstemmed Subseismic to Seismic Slip in Smectite Clay Nanofoliation
title_short Subseismic to Seismic Slip in Smectite Clay Nanofoliation
title_sort subseismic to seismic slip in smectite clay nanofoliation
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6919425/
https://www.ncbi.nlm.nih.gov/pubmed/31894196
http://dx.doi.org/10.1029/2019JB017364
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