Early folds (F 1 ) in the Mylor beds are upright or overturned to the north-west and trend north-easterly. They are cut by a flat-lying cleavage (S 2 ) which is related to small-scale recumbent folds (F 2 ) superimposed on the steep limbs of the early folds. The sequence of development of folds can be found elsewhere in the Mylor-Gramscatho beds and also in the Lizard Head mica schists. It is shown that F 2 folds and S 2 cleavage resulted from vertical shortening, which is believed to have been caused by the superimposition of slide sheets. It is suggested that the previously accepted age order of the Mylor and Gramscatho beds should be reversed.