Publication Date:
2020-02-24
Description:
Active faults in the upper crust can either slide steadily by
aseismic creep, or abruptly causing earthquakes. Creep relaxes the
stress and prevents large earthquakes from occurring. Identifying
the mechanisms controlling creep, and their evolution with time and
depth, represents a major challenge for predicting the behavior of
active faults. Based on microstructural studies of rock samples collected
from the San Andreas Fault Observatory at Depth (California),
we propose that pressure solution creep, a pervasive deformation
mechanism, can account for aseismic creep. Experimental data
on minerals such as quartz and calcite are used to demonstrate that
such creep mechanism can accommodate the documented 20 mm/yr
aseismic displacement rate of the San Andreas fault creeping zone.
We show how the interaction between fracturing and sealing controls
the pressure solution rate, and discuss how such a stress-driven
mass transfer process is localized along some segments of the fault.
Description:
Published
Description:
1131-1134
Description:
JCR Journal
Description:
restricted
Keywords:
Faults
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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