A new source of water in seismogenic subduction zones

Details A new source of water in seismogenic subduction zones A new source of water in seismogenic subduction zones

Nov 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011georl..3822306k&link_type=abstract

Geophysical Research Letters, Volume 38, Issue 22, CiteID L22306

Physics

Mineral Physics: X-Ray, Neutron, And Electron Spectroscopy And Diffraction, Seismology: Subduction Zones (1207, 1219, 1240), Structural Geology: Role Of Fluids, Tectonophysics: Subduction Zone Processes (1031, 3060, 3613, 8413)

Scientific paper

Seismogenic plate-boundary faults at accretionary margins (e.g., the Nankai margin, southwest Japan) may occur where the uppermost part of subducting oceanic crust, composed of basaltic rocks, is in contact with the overriding plate of a lithified accretionary prism. The plate-boundary faults in ancient accretionary complexes typically record high-velocity slip under fluid-rich conditions. Although previous studies have emphasized the mechanical significance of fluids in terms of dynamic slip-weakening, the source of fluid in seismogenic subduction zones remains poorly constrained. In this work, we focus on the hydrous smectite in the uppermost oceanic crust, an alteration product of intact basalt before arrival at the trench axis. A comparison between (1) new mineralogical data on basalt drillcore recovered by Integrated Ocean Drilling Program (IODP) Expedition 322 at site C0012, a reference site for subduction input to the Nankai Trough, and (2) mineralogical data on basalt within ancient oceanic crust embedded in a fossil accretionary complex of the Shimanto Belt, southwest Japan, suggests that progressive smectite-chlorite conversion would liberate bound fluids at a rate of 0.34 to 0.65 × 10-14 s-1 along the plate interface. This rate of fluid production appears to be more than an order of magnitude greater than that from other possible sources, including from overlying sediments via smectite-illite conversion and the expulsion of pore fluids, and may facilitate seismic slip along plate-boundary faults.

Affiliated with

Also associated with

No associations

Rating

A new source of water in seismogenic subduction zones does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A new source of water in seismogenic subduction zones, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A new source of water in seismogenic subduction zones will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-739497