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Growth or syntectonic strata are stratigraphic intervals that were deposited during deformation. The ages of growth strata therefore define the timing of deformations. In contractional fault-related folds, growth strata typically thin across fold limbs toward structural highs. The geometries of growth structures are controlled primarily by the folding mechanism and the relative rates of sedimentation and uplift. Thus, growth fold patterns imaged in seismic data are often considered diagnostic of folding mechanism and sediment-to-uplift ratio. In this article, we describe common patterns of growth strata in fault-related folds that are imaged in seismic reflection data.

Growth or syntectonic strata are stratigraphic intervals that were deposited during [[deformation]]. The ages of growth strata therefore define the timing of deformations. In contractional fault-related folds, growth strata typically thin across fold limbs toward structural highs. The geometries of growth structures are controlled primarily by the folding mechanism and the relative rates of sedimentation and uplift. Thus, growth fold patterns imaged in seismic data are often considered diagnostic of folding mechanism and sediment-to-uplift ratio. In this article, we describe common patterns of growth strata in fault-related folds that are imaged in seismic reflection data.

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[[File:ST53Part01Pg13.jpg|thumb|300px|{{figure number|5}}]]

[[File:ST53Part01Pg13.jpg|thumb|300px|{{figure number|5}}]]

The seismic section [[:file:ST53Part01Pg13.jpg|Figure 5, left]] shows a narrowing upward fold limb, or growth triangle, where bed dips within the fold limb generally do not shallow upward, consistent with folding by kink-band migration. Dipmeter data in the wells corroborates the reflector dips. In the section in [[:file:ST53Part01Pg13.jpg|Figure 5, top right]], a fanning and upward shallowing of limb dips within growth strata are consistent with folding by progressive limb rotation. The core of the anticline is filled with salt, which presumably thickened during deformation, leading to progressive rotation of the overlying fold limbs. The growth structure in the section in [[:file:ST53Part01Pg13.jpg|Figure 5, lower right]] contains both a growth triangle and a fanning of limb dips, suggesting folding by a combination of kink-band migration and limb rotation mechanisms. Kinematic theories that employ hybrid folding mechanisms include shear fault-bend folds,<ref name=Suppeetal_2004>Suppe, J., C. Connors, and Y. Zhang, 2004, [http://archives.datapages.com/data/specpubs/memoir82/CHAPTER16/CHAPTER16.HTM Shear fault-bend folding], ''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. 303-323.</ref> certain classes of detachment folds,<ref name=Dahlstrom_1990 /><ref name=Hardyandpoblet_1994 /> and trishear fault-propagation folds.<ref name=Ersley_1991>Ersley, E. A., 1991, [http://geology.gsapubs.org/content/19/6/617.abstract Trishear fault-propagation folding]: Geology, v. 19, no. 6, p. 617-620.</ref><ref name=Hardyandford_1997>Hardy, S., and M. Ford, 1997, [http://onlinelibrary.wiley.com/doi/10.1029/97TC01171/full Numerical modeling of trishear fault-propagation folding and associated growth strata]: Tectonics, v. 16, no. 5, p. 841-854.</ref><ref name=Allmendinger_1998>Allmendinger, R. W., 1998, [http://onlinelibrary.wiley.com/doi/10.1029/98TC01907/full Inverse and forward numerical modeling of trishear fault-propagation folds]: Tectonics, v. 17, no. 4, p. 640-656.</ref>

The seismic section [[:file:ST53Part01Pg13.jpg|Figure 5, left]] shows a narrowing upward fold limb, or growth triangle, where bed dips within the fold limb generally do not shallow upward, consistent with folding by kink-band migration. Dipmeter data in the wells corroborates the reflector dips. In the section in [[:file:ST53Part01Pg13.jpg|Figure 5, top right]], a fanning and upward shallowing of limb dips within growth strata are consistent with folding by progressive limb rotation. The core of the anticline is filled with salt, which presumably thickened during [[deformation]], leading to progressive rotation of the overlying fold limbs. The growth structure in the section in [[:file:ST53Part01Pg13.jpg|Figure 5, lower right]] contains both a growth triangle and a fanning of limb dips, suggesting folding by a combination of kink-band migration and limb rotation mechanisms. Kinematic theories that employ hybrid folding mechanisms include shear fault-bend folds,<ref name=Suppeetal_2004>Suppe, J., C. Connors, and Y. Zhang, 2004, [http://archives.datapages.com/data/specpubs/memoir82/CHAPTER16/CHAPTER16.HTM Shear fault-bend folding], ''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. 303-323.</ref> certain classes of detachment folds,<ref name=Dahlstrom_1990 /><ref name=Hardyandpoblet_1994 /> and trishear fault-propagation folds.<ref name=Ersley_1991>Ersley, E. A., 1991, [http://geology.gsapubs.org/content/19/6/617.abstract Trishear fault-propagation folding]: Geology, v. 19, no. 6, p. 617-620.</ref><ref name=Hardyandford_1997>Hardy, S., and M. Ford, 1997, [http://onlinelibrary.wiley.com/doi/10.1029/97TC01171/full Numerical modeling of trishear fault-propagation folding and associated growth strata]: Tectonics, v. 16, no. 5, p. 841-854.</ref><ref name=Allmendinger_1998>Allmendinger, R. W., 1998, [http://onlinelibrary.wiley.com/doi/10.1029/98TC01907/full Inverse and forward numerical modeling of trishear fault-propagation folds]: Tectonics, v. 17, no. 4, p. 640-656.</ref>

==Distinguishing drape from growth strata==

==Distinguishing drape from growth strata==