Definition of "crumpling"

Watt saw the little movements of the stuff, the little bulgings and crumplings, and the sudden indrawings, where it was nipped, between forefinger and thumb probably, for those are the nippers.

1953, Samuel Beckett, Watt, 1st American edition, New York, N.Y.: Grove Press, published 1959

When strata are so unsymmetrically and abundantly folded that it becomes difficult or impossible to trace out the individual flexures and crumplings — the whole forming an irregular complex of folds — they are said to be contorted […]

1905, James Geikie, Structural and Field Geology: For Students of Pure and Applied Science