Kinematic analysis of shear zones in sandstone and mudstone of the Shimanto belt, Shikoku, SW Japan

1990 ◽  
Vol 12 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Darrel S Cowan
Keyword(s):  
Kinematic Analysis ◽  
Shear Zones ◽  
Shimanto Belt ◽  
Sw Japan

scholarly journals Hydrous oceanic crust hosts megathrust creep at low shear stresses

2020 ◽  
Vol 6 (22) ◽  
pp. eaba1529
Author(s):  
Christopher J. Tulley ◽  
Åke Fagereng ◽  
Kohtaro Ujiie
Keyword(s):  
Oceanic Crust ◽  
Shear Zones ◽  
Interface Strength ◽  
Shear Stresses ◽  
Plate Interface ◽  
Strength And Deformation ◽  
Transition Field ◽  
Flow Laws ◽  
Sw Japan ◽  
Low Shear

The rheology of the metamorphosed oceanic crust may be a critical control on megathrust strength and deformation style. However, little is known about the strength and deformation style of metamorphosed basalt. Exhumed megathrust shear zones exposed on Kyushu, SW Japan, contain hydrous metabasalts deformed at temperatures between ~300° and ~500°C, spanning the inferred temperature-controlled seismic-aseismic transition. Field and microstructural observations of these shear zones, combined with quartz grain-size piezometry, indicate that metabasalts creep at shear stresses <100 MPa at ~370°C and at shear stresses <30 MPa at ~500°C. These values are much lower than those suggested by viscous flow laws for basalt. The implication is that relatively weak, hydrous, metamorphosed oceanic crust can creep at low viscosities over a wide shear zone and have a critical influence on plate interface strength and deformation style around the seismic-aseismic transition.

Fluid overpressure along an Oligocene out-of-sequence thrust in the Shimanto Belt, SW Japan

2014 ◽  
Vol 86 ◽  
pp. 12-24 ◽  
Author(s):  
François X. Passelègue ◽  
Olivier Fabbri ◽  
Michel Dubois ◽  
Sandra Ventalon
Keyword(s):  
Shimanto Belt ◽  
Sw Japan

Strain and kinematic analysis in general shear zones

1993 ◽  
Vol 15 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Carol Simpson ◽  
Declan G. De Paor
Keyword(s):  
Kinematic Analysis ◽  
Shear Zones
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