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Figure F65. Digital photomicrograph of Sample 179-1105A-29R-1, 102-106 cm, shows a mylonite zone marked by oxide, a mylonite band, and a sharp contact between a coarser domain containing porphyroclastic textures with larger plagioclase neoblasts and a finer domain of mylonitic opaque oxide and plagioclase neoblasts surrounding small clinopyroxene porphyroclasts. An opaque oxide-rich zone shows its effect in localizing ductile strain. There is apparently a significant ductility contrast across the domain contact marked by the appearance of oxides. Coarser grained domains (coarser porphyroclastic texture) are affected by brittle synthetic or Riedel shears, which dissect neoblasts and porphyroclasts of plagioclase. Opaque oxide zones only show ductile deformation, and Reidels shears disappear into the oxide zone as they cross the domain contact. Also note dynamic recrystallization of clinopyroxene porphyroclasts in the coarser domain (cross-polarized light; field of view = 5.5 mm).

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