Monazite as a monitor of shear strain in orogenic crust

The Ramsay-Graham heterogeneous simple shear zone model revolutionized our understanding of finite strain variation in orogenic belts. Many deeply exhumed (>20 km depths) zones continental crust are a consequence sub-simple accumulation during contraction and displacement at high temperature. Here we explore the micro-scale record this process using syn-kinematic monazite two >20,000 km2 terrane lower crust. Field observations combined with high-spatial resolution X-ray mapping, Th–U-Pb electron microprobe petrochronology, backscatter diffraction analysis demonstrate that grains can provide an important textural temporal mylonite ultramylonite gneisses. Monazite exhibit aspect ratios 1.7–4.6 parallel to stretching lineation or oblique (<30°) penetrative foliation. EBSD data for grain orientation spread, i.e., average misorientation relative mean, consistent no significant dislocation-accommodated internal deformation. We conclude dissolution precipitation creep produced compositionally-defined geometries compatible dextral sense observed outcrop thin section. Syn-kinematic rims on develop low domains absolute ages μm-to km-scale kinematics orogens.