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Two folding mechanisms — kink-band migration and limb rotation — are commonly ascribed to contractional fault-related folds. These folding mechanisms typically yield distinctive patterns of deformed growth strata above fold limbs. Thus, seismic images of growth folds can be used to identify the folding mechanisms, which in turn can dictate the kinematic theory (e.g., fault-bend folding or detachment folding) that is most appropriate to guide the structural interpretation of the seismic data.

Two folding mechanisms — kink-band migration and limb rotation — are commonly ascribed to contractional fault-related folds. These folding mechanisms typically yield distinctive patterns of deformed growth strata above fold limbs. Thus, seismic images of growth folds can be used to identify the folding mechanisms, which in turn can dictate the kinematic theory (e.g., fault-bend folding or detachment folding) that is most appropriate to guide the structural interpretation of the seismic data.

In fault-related folds that develop purely by kink-band migration, fold limbs widen through time while maintaining a fixed dip,<ref name=Suppeetal_1992>Suppe, J., G. T. Chou, and S. C. Hook, 1992, [http://link.springer.com/chapter/10.1007%2F978-94-011-3066-0_9 Rates of folding and faulting determined from growth strata], ''in'' K. R. McClay, ed., Thrust tectonics; London, Chapman, and Hall, p. 105-121.</ref> as illustrated in the sequential model involving pre-growth strata only ([[:file:ST53Part01Pg12A.jpg|Figure 3, left]]). Material is incorporated into the fold limb by passing through an active axial surface, which at depth is generally pinned to a bend or tip of a fault.<ref name=Suppe_1983>Suppe, J., 1983, [http://www.ajsonline.org/content/283/7/684.short Geometry and kinematics of fault-bend folding]: American Journal of Science, v. 283, p. 684-721.</ref><ref name=Suppeandmedwedeff_1990>Suppe, J., and D. A. Medwedeff, 1990, Geometry and kinematics of fault-propagation folding: Ecolg. Geol. Helf., v. 83, p. 409-454.</ref> The fold limb in growth strata is bounded by the active axial surface and the growth axial surface, an inactive axial surface that defines the locus of particles originally deposited along the active axial surface. In these sequential models ([[:file:ST53Part01Pg12A.jpg|Figure 3, left side]]), the synclinal axial surface is active, and the anticlinal axial surface is inactive.

In fault-related folds that develop purely by kink-band migration, fold limbs widen through time while maintaining a fixed [[dip]],<ref name=Suppeetal_1992>Suppe, J., G. T. Chou, and S. C. Hook, 1992, [http://link.springer.com/chapter/10.1007%2F978-94-011-3066-0_9 Rates of folding and faulting determined from growth strata], ''in'' K. R. McClay, ed., Thrust tectonics; London, Chapman, and Hall, p. 105-121.</ref> as illustrated in the sequential model involving pre-growth strata only ([[:file:ST53Part01Pg12A.jpg|Figure 3, left]]). Material is incorporated into the fold limb by passing through an active axial surface, which at depth is generally pinned to a bend or tip of a fault.<ref name=Suppe_1983>Suppe, J., 1983, [http://www.ajsonline.org/content/283/7/684.short Geometry and kinematics of fault-bend folding]: American Journal of Science, v. 283, p. 684-721.</ref><ref name=Suppeandmedwedeff_1990>Suppe, J., and D. A. Medwedeff, 1990, Geometry and kinematics of fault-propagation folding: Ecolg. Geol. Helf., v. 83, p. 409-454.</ref> The fold limb in growth strata is bounded by the active axial surface and the growth axial surface, an inactive axial surface that defines the locus of particles originally deposited along the active axial surface. In these sequential models ([[:file:ST53Part01Pg12A.jpg|Figure 3, left side]]), the synclinal axial surface is active, and the anticlinal axial surface is inactive.

In the case where sedimentation rate exceeds uplift rate ([[:file:ST53Part01Pg12A.jpg|Figure 3, center]]), strata are folded through the synclinal axis and incorporated into the widening fold limb. The dip of folded growth strata is equal to dip of the fold limb in pre-growth strata. The width of the dip panel for each growth horizon corresponds to the amount of fold growth that occurred subsequent to the deposition of that marker. As a result, younger horizons have narrower fold limbs than do older horizons, forming narrowing upward fold limbs or kink bands in growth strata (growth triangles). In the case where uplift rate exceeds sedimentation rate ([[:file:ST53Part01Pg12A.jpg|Figure 3, right side]]), each increment of folding produces a discrete fold scarp located where the active axial surface projects to the Earth’s surface.<ref name=Shawetal_2004>Shaw, J. H., E. Novoa, and C. Connors, 2004, [http://archives.datapages.com/data/specpubs/memoir82/CHAPTER20/CHAPTER20.HTM Structural controls on growth stratigraphy in contractional fault-related folds], ''in'' K. R. McClay, ed., Thrust tectonics and hydrocarbon systems: [http://archives.datapages.com/data/alt-browse/aapg-special-volumes/m82.htm AAPG Memoir 82], p. 400-412.</ref> Subsequent deposits onlap the fold scarp, producing stratigraphic pinchouts above the fold limb. Fold scarps and stratigraphic pinch-outs are displaced laterally and folded as they are incorporated into widening limbs.

In the case where sedimentation rate exceeds uplift rate ([[:file:ST53Part01Pg12A.jpg|Figure 3, center]]), strata are folded through the synclinal axis and incorporated into the widening fold limb. The dip of folded growth strata is equal to dip of the fold limb in pre-growth strata. The width of the dip panel for each growth horizon corresponds to the amount of fold growth that occurred subsequent to the deposition of that marker. As a result, younger horizons have narrower fold limbs than do older horizons, forming narrowing upward fold limbs or kink bands in growth strata (growth triangles). In the case where uplift rate exceeds sedimentation rate ([[:file:ST53Part01Pg12A.jpg|Figure 3, right side]]), each increment of folding produces a discrete fold scarp located where the active axial surface projects to the Earth’s surface.<ref name=Shawetal_2004>Shaw, J. H., E. Novoa, and C. Connors, 2004, [http://archives.datapages.com/data/specpubs/memoir82/CHAPTER20/CHAPTER20.HTM Structural controls on growth stratigraphy in contractional fault-related folds], ''in'' K. R. McClay, ed., Thrust tectonics and hydrocarbon systems: [http://archives.datapages.com/data/alt-browse/aapg-special-volumes/m82.htm AAPG Memoir 82], p. 400-412.</ref> Subsequent deposits onlap the fold scarp, producing stratigraphic pinchouts above the fold limb. Fold scarps and stratigraphic pinch-outs are displaced laterally and folded as they are incorporated into widening limbs.