posted on 2020-07-20, 15:24authored byHe Feng, Christopher Gerbi, Scott E. Johnson
<p>Strain localization occurs under different geological scales and
in both the brittle and viscous regimes, as the one of most significant processes
of solid earth. The earliest stages of strain concentration essential to
determining the cause(s) of localization. Bridge zone, or "interconnection
of weak phases", occurs in less deformed, which reveals initialization of
localization. These “bridge zones” comprise reduced grain sizes and an
aggregation of relatively fine grains in a narrow band. Combined
optical, electron beam petrography with cathodoluminescence (CL) and
electron backscatter diffraction (EBSD) are used to characterize these “bridge
zones”: 1. Bridge zones result from not only in-situ grain size reduction (such
as recrystallization or cataclasis), but some chemical processes (not major
elements) for phase mixing or element discharging on a short spatial scale; 2.
The Bridge zone can be observed in wide range of P-T conditions; 3. Bridge zone
is an aggregation of relatively fine grains in a narrow band and mechanically
links rheologically weak phases or domains, which is weaker than the domains it
replaced, and efficiently reduces the bulk strength of rock. </p><br>