Competent bed

Competent bed: A rock layer which, during folding, flexes without appreciable flow or internal shear. In metamorphosed rocks a competent bed will not develop slaty cleavage. (See Incompetent bed.) Competency of rocks is a relative term depending to some extent on the surrounding rocks, i.e. a rock in one situation may act as a competent horizon while in other circumstances an identical rock may act incompetently.