Chevron (geology)

Chevron folds with flat-lying axial planes, Millook Haven, North Cornwall, UK

Chevron folds are a structural feature characterized by repeated well behaved folded beds with straight limbs and sharp hinges. Well developed, these folds develop repeated set of v-shaped beds.[1] They develop in response to regional or local compressive stress. Inter-limb angles are generally 60 degrees or less. Chevron folding preferentially occurs when the bedding regularly alternates between contrasting competences.[1] Turbidites, characterized by alternating high-competence sandstones and low-competence shales, provide the typical geological setting for chevron folds to occur.

Perpetuation of the fold structure is not geometrically limited. Given a proper stratigraphy, chevrons can persist almost indefinitely.[2]

  1. ^ a b Ramsay, J (1974). "Development of chevron folds". Geological Society of America Bulletin. 85 (11): 1741. Bibcode:1974GSAB...85.1741R. doi:10.1130/0016-7606(1974)85<1741:docf>2.0.co;2.
  2. ^ Reches, Z E; Johnson (1976). "A theory of concentric, kink and sinusoidal folding and of monoclinal flexuring of compressible, elastic multilayers: VI. Asymmetric folding and monoclinal kinking". Tectonophysics. 35 (4): 295–334. Bibcode:1976Tectp..35..295R. doi:10.1016/0040-1951(76)90074-3.