Structural features of natural chevron folds were studied in north Cornwall, England and an experiment was performed to simulate these structures. The study reveals that the amount of interstitial flow (Biot, 1965) varies along the fold limb and this variation is attributed to the formation of, (1) limb thinning and hinge thickening, (2) variation in the intensity of development of extension faults along the fold limb, and (3) development of overlapping boudins.