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Role of dynamic grain boundary wetting in fluid circulation beneath volcanic arcs
Author(s) -
HierMajumder Saswata,
Kohlstedt David L.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl025716
Subject(s) - wetting , geology , shear (geology) , grain boundary , permeability (electromagnetism) , olivine , shear zone , microstructure , mineralogy , petrology , materials science , composite material , tectonics , paleontology , membrane , biology , genetics
We report the influence of shear deformation on the microstructure of water‐saturated olivine and clinopyroxene aggregates. Prior to deformation, the aqueous fluid was isolated in pockets along grain corners in the olivine‐water aggregates, while it was interconnected by a network of grain‐edge tubules in the clinopyroxene‐water aggregate. During deformation of both types of aggregates, the aqueous fluid phase segregates into grain boundaries at an angle of ∼16° to the shear direction, inclined in a sense antithetic to the applied shear. Fluid‐rich planes formed by such dynamic wetting of grain boundaries lead to the formation of high permeability paths in the matrix. In a deforming mantle, such high permeability paths will enhance the efficiency of aqueous fluid extraction from subducting slabs.