Fig. 7: EBSD analyses of Cpx2 grains of a high-strain experiment.
From: Deep crustal deformation driven by reaction-induced weakening
a CPO, SPO and aspect ratio (AR) evolution as a function of grain size (OR114). Pole figures (PF) were constructed with isocontours using equal-area lower-hemisphere projections based on the mean orientation of grains. n = number of data point; J = texture index; M = misorientation index; MUD = multiple of uniform distribution. b, c Maps of a high-strain shear zone (zoom over Fig. 6). b Phase map of Cpx with red lines corresponding to subgrain boundaries, here defined as pixel-to-pixel lattice misorientations between 2° and 10°. c Orientation map of Cpx grains color-coded based on the orientation of their crystal reference frame (inverse pole figure) with respect to the shear direction (X). d CPO of Cpx grains displayed in equal area lower-hemisphere pole figures for different areas around a C’-type shear band, including a pressure shadow of a Cpx1 porphyroclast (blue area). While Cpx grains do not show any CPO in the pressure shadow (blue PF), a CPO develops (orange PF) and strengthens (red PF) as strain increases in the shear band. The fabric strength (J and M) remains however very weak regarding the amount of finite shear strain (γ) calculated based on the angle (38°) between the foliation (S) and the shear plane (C’)43,44. Source data are provided as a Source Data file.
