Fig. 2
From: Ripplocations provide a new mechanism for the deformation of phyllosilicates in the lithosphere
Diamond-shaped expansion structure arrays. Brightfield transmission electron microscope micrographs of focussed ion beam-prepared biotite specimens from mylonitic orthogneiss. a Bright streaks parallel to the basal plane, but stacked in two principle orientations, produce elongated, diamond-shaped arrays across the entirety of biotite grains. The acute angles of these diamonds measure between 30° and 60°. b At higher magnifications, these streaks are revealed to be up to 60 Å wide, lozenge-shaped lattice expansion (or delamination) structures of the biotite basal planes. c Detail of expansion structures/delaminations stacked in en-echelon arrays. d Schematic of the features observed in a–c showing the en-echelon stacking of lozenge-shaped expansion structures/delaminations offsetting TMT layers and producing diamond-shaped arrays
