1. Mesoscopic structures associated with the Bermagui Megakink
- Author
-
Thomas J. Cudahy
- Subjects
Mesoscopic physics ,Deformation (mechanics) ,Geometry ,Rotation ,Crystallography ,Crenulation ,Orientation (geometry) ,Earth and Planetary Sciences (miscellaneous) ,Foliation (geology) ,General Earth and Planetary Sciences ,Dilation (morphology) ,Compression (geology) ,Nonlinear Sciences::Pattern Formation and Solitons ,Geology - Abstract
The final deformation in a polydeformed unit of Ordovician turbidites along the NSW south coast, produced kinks at scales from centimetres (mesoscopic kinks) to kilometres (megakinks). At the outcrop‐scale, crenulation cleavages and fractures also developed. The mesoscopic kinks are of the reverse type, have orthorhombic to monoclinic symmetry and generally show a small dilation of the kink short‐limb. An S3 crenulation cleavage is associated with the kinks and shows variable morphology and orientation. The kinks are interpreted to have formed by a modified “kink rotation model’, in which kink‐band foliation shortens during kink formation. The mesoscopic kink geometry does not uphold both the kink proportion compressional analysis and the conjugate kink bisector method for determining the axis of principal compression. Nevertheless, both methods suggest that the mesoscopic kinks predate the megakink rotation.
- Published
- 1986
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