ZONE OF CONTACT STRAIN

The photograph from Rhoscolyn in Anglesey shows that the zone of contact strain of individual layers did not interfere with that of another layer and each layer began buckling as a single layer but after the folding had advanced to some extent they did. The uppermost layer buckled with very large layer parallel shortening, the middle with presumably equal amount of layer parallel strain and buckling strain and lowermost thin layer with mostly buckling strain. This photograph, originally in B and W taken in 1976 by the author won in 1982 the highest Silver Hammer Prize at the All India Geological Photographs Competition. It is an ideal text book example of the phenomenon.