Kinetic Models for Healing of the Subduction Interface Based on Observations of Ancient Accretionary Complexes
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- D. M. Fisher
- Department of Geosciences Penn State University University Park PA USA
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- A. J. Smye
- Department of Geosciences Penn State University University Park PA USA
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- C. Marone
- Department of Geosciences Penn State University University Park PA USA
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- P. E. van Keken
- Department of Terrestrial Magnetism Carnegie Institution for Science Washington DC USA
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- A. Yamaguchi
- Department of Ocean Floor Geoscience, Atmosphere and Ocean Research Institute The University of Tokyo Kashiwa Japan
書誌事項
- 公開日
- 2019-07
- 資源種別
- journal article
- 権利情報
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- http://onlinelibrary.wiley.com/termsAndConditions#am
- http://onlinelibrary.wiley.com/termsAndConditions#vor
- DOI
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- 10.1029/2019gc008256
- 公開者
- American Geophysical Union (AGU)
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説明
<jats:title>Abstract</jats:title><jats:p>Sand‐shale mélanges from the Kodiak accretionary complex and Shimanto belt of Japan record deformation during underthrusting along a paleosubduction interface in the range 150 to 350 °C. We use observations from these mélanges to construct a simple kinetic model that estimates the maximum time required to seal a single fracture as a measure of the rate of fault zone healing. Crack sealing involves diffusive redistribution of Si from mudstones with scaly fabric to undersaturated fluid‐filled cracks in sandstone blocks. Two driving forces are considered for the chemical potential gradient that drives crack sealing: (1) a transient drop in fluid pressure <jats:italic>∆P</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>, and (2) a difference in mean stress between scaly slip surfaces in mudstones and cracks in stronger sandstone blocks. Sealing times are more sensitive to mean stress than <jats:italic>∆P</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>, with up to four orders of magnitude faster sealing. Sealing durations are dependent on crack spacing, silica diffusion kinetics, and magnitude of the strength contrast between block and matrix, each of which is loosely constrained for conditions relevant to the seismogenic zone. We apply the model to three active subduction zones and find that sealing rates are fastest along Cascadia and several orders of magnitude slower for a given depth along Nicaragua and Tohoku slab‐top geotherms. The model provides (1) a framework for geochemical processes that influence subduction mechanics via crack sealing and shear fabric development and (2) demonstration that kinetically driven mass redistribution during the interseismic period is a plausible mechanism for creating asperities along smooth, sediment‐dominated convergent margins.</jats:p>
収録刊行物
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- Geochemistry, Geophysics, Geosystems
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Geochemistry, Geophysics, Geosystems 20 (7), 3431-3449, 2019-07
American Geophysical Union (AGU)
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詳細情報 詳細情報について
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- CRID
- 1361131418079680000
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- ISSN
- 15252027
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- Web Site
- https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2019GC008256
- https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019GC008256
- https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2019GC008256
- https://agupubs.onlinelibrary.wiley.com/doi/am-pdf/10.1029/2019GC008256
- https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019GC008256
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- 資料種別
- journal article
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- データソース種別
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- Crossref
- KAKEN
- OpenAIRE
