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Non-cylindrical folds, linear structures in the X direction and mylonite developed during translation of the Caledonian Kalak Nappe Complex of Finnmark

Published online by Cambridge University Press:  01 May 2009

S. Rhodes
Affiliation:
Geology Department, University College, Cardiff, Wales
R. A. Gayer
Affiliation:
Geology Department, University College, Cardiff, Wales

Summary

Structural evidence from the Kalak Nappe Complex suggests the operation of layer parallel shearing stresses during the translation of the nappes. A simple shear model invoking irregular areas of high cohesion within individual layer boundaries is used to explain the development of both intra-folial, cylindrical and non-cylindrical folds and a regular zone of syn-folding blasto-mylonite at the base of the nappe(s). Fold hinges that are initially developed parallel to the Y axis of the strain ellipsoid during layer parallel shearing may be rotated towards the X direction as a result of large strains concentrated at points of high cohesion within the layering boundaries.

Type
Articles
Copyright
Copyright © Cambridge University Press 1977

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