Folds and Folding Mechanisms

Folds and Folding Mechanisms#

This lecture introduces folds morphology, their classifications and the folding mechanisms.

PDF, Updated Oct 06, 2021

Learning outcomes#

At the end of the lecture, students will be able to:

  • classify folds according to fold terminology

  • understand folding mechanisms

  • find second order folds and cleavage

  • identify folding and faulting in extensional regimes

  • identify folding and faulting in compressional regimes

Glossary#

  • Anticline

  • Anticlinorium

  • Antiform

  • Axial Surface

  • Axial trace

  • Basin

  • Bending

  • Buckling

  • Crest line

  • Culmination

  • Depression

  • Dome

  • Elastica

  • Facing Direction

  • Fold, accordion

  • Fold, amplitude

  • Fold, assymetric

  • Fold, axial plane or axial surface of

  • Fold, axial trace of

  • Fold, axial trend of

  • Fold, axis

  • Fold, box

  • Fold, chevron

  • Fold, close

  • Fold, conical

  • Fold, conjugate

  • Fold, cylindrical

  • Fold, domain: part of the fold delimited by inflexion lines. Domains with negative curvature (Upward closing) are called antiforms, domains with positive curvature (downward closing) are synforms.

  • Fold, en-echelon

  • Fold, eyed

  • Fold, facing direction of

  • Fold, gentle

  • Fold, inclined

  • Fold, interlimb angle of

  • Fold, isoclinal

  • Fold, kink

  • Fold, limb

  • Fold, neutral

  • Fold, non-cylindrical

  • Fold, open

  • Fold, parasitic

  • Fold, polyclinal

  • Fold, polyharmonic

  • Fold, tight

  • Fold, upright

  • Fold, vertical

  • Fold, wavelength

  • Fold, zigzag

  • Hinge line: Lines joining the points of minimum curvature and lines joining the points of maximum curvature.

  • Hinge line surface

  • Hinge zone

  • Inflexion line: Lines joining the points of zero curvature.

  • Inflexion line surface

  • Interlimb angle

  • Inverted saddle

  • Median surface

  • Monocline

  • Saddle

  • Syncline

  • Synclinorium

  • **Synform

  • **Trough line

  • **Wavelength

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