Changes

===Cross-Sectional Clinoform Geometry===

===Cross-Sectional Clinoform Geometry===

The shape and dip angle of a deltaic or shoreface clinoform in [[cross section]] is a function of modal grain size, proportion of mud, and the depositional process regime at the shoreline. In sandy, fluvial-dominated deltas, clinoforms have simple concave-upward geometries and steep dip angles (up to 15°)<ref name=GB05 /> (e.g., [[:File:BLTN13190fig1.jpg|Figure 1]]). Similar geometries have been documented in sandy, tide-influenced deltas (dip angles up to 5°–15°).<ref name=Wllsetal1999>Willis, B. J., J. P. Bhattacharya, S. L. Gabel, and C. D. White, 1999, Architecture of a tide-influenced river delta in the Frontier Formation of central Wyoming, USA: Sedimentology, v. 46, no. 4, p. 667–688, doi: 10.1046/j.1365-3091.1999.00239.x.</ref> Concave-upward clinoform geometry is also typical of sandy, wave-dominated deltas and strandplains, although the clinoforms have smaller dip angles (typically up to 1°–2°).<ref>Hampson, G. J., and J. E. A. Storms, 2003, Geomorphological and sequence stratigraphic variability in wave-dominated shoreface-shelf parasequences: Sedimentology, v. 50, no. 4, p. 667–701, doi: 10.1046/j.1365-3091.2003.00570.x.</ref><ref name=GB05 /> Clinoforms are consistently inclined paleobasinward down depositional dip; and, along depositional strike, they exhibit bidirectional, concave-upward dips if the delta-front was lobate in plan view (e.g., Willis et al.;<ref name=Wllsetal1999 /> Kolla et al.;<ref name=Kll>Kolla, V., P. Biondi, B. Long, and R. Fillon, 2000, Sequence stratigraphy and architecture of the late Pleistocene Lagniappe delta complex, northeast Gulf of Mexico, inD. Hunt, and R. L. Gawthorpe, eds., Sedimentary responses to forced regressions: Geological Society, London, Special Publication 172, p. 291–327.</ref> Roberts et al.<ref name=Rbrts2004 />) or appear horizontal if the shoreline was approximately linear (e.g., Hampson<ref name=Hmpsn2000 />). Clinoforms are usually truncated at their tops by a variety of channelized erosion surfaces formed during shoreline advance (e.g., distributary channels, incised valleys) and by channelized and/or planar transgressive erosion surfaces (tide and wave ravinement surfaces sense Swift<ref>Swift, D. J., 1968, Coastal erosion and transgressive stratigraphy: Journal of Geology, v. 76, no. 4, p. 444–456, doi: 10.1086/jg.1968.76.issue-4.</ref>) associated with shoreline retreat. Consequently, most sandy shoreline clinoforms lack a decrease in depositional dip (rollover) near their tops, although this geometry is ubiquitous in larger, shelf-slope margin clinoforms (e.g., Steckler et al.<ref name=Stcklr1999>Steckler, M. S., G. S. Mountain, K. G. Miller, and N. Christie-Blick, 1999, Reconstruction of tertiary progradation and clinoform development on the New Jersey passive margin by 2D backstripping: Marine Geology, v. 154, no. 1–4, p. 399–420, doi: 10.1016/S0025-3227(98)00126-1.</ref>) and in the outer, muddy portion of compound deltaic clinoforms with a broad subaqueous topset that lies seaward of the shoreline (e.g., Pirmez et al.<ref>Pirmez, C., L. F. Pratson, and M. S. Steckler, 1998, Clinoform development by advection-diffusion of suspended sediment; modeling and comparison to natural systems: Journal of Geophysical Research B: Solid Earth and Planets, v. 103, p. 24,141–24,157, doi: 10.1029/98JB01516.</ref>).

The shape and dip angle of a deltaic or shoreface clinoform in [[cross section]] is a function of modal [[grain size]], proportion of mud, and the depositional process regime at the shoreline. In sandy, fluvial-dominated deltas, clinoforms have simple concave-upward geometries and steep dip angles (up to 15°)<ref name=GB05 /> (e.g., [[:File:BLTN13190fig1.jpg|Figure 1]]). Similar geometries have been documented in sandy, tide-influenced deltas (dip angles up to 5°–15°).<ref name=Wllsetal1999>Willis, B. J., J. P. Bhattacharya, S. L. Gabel, and C. D. White, 1999, Architecture of a tide-influenced river delta in the Frontier Formation of central Wyoming, USA: Sedimentology, v. 46, no. 4, p. 667–688, doi: 10.1046/j.1365-3091.1999.00239.x.</ref> Concave-upward clinoform geometry is also typical of sandy, wave-dominated deltas and strandplains, although the clinoforms have smaller dip angles (typically up to 1°–2°).<ref>Hampson, G. J., and J. E. A. Storms, 2003, Geomorphological and sequence stratigraphic variability in wave-dominated shoreface-shelf parasequences: Sedimentology, v. 50, no. 4, p. 667–701, doi: 10.1046/j.1365-3091.2003.00570.x.</ref><ref name=GB05 /> Clinoforms are consistently inclined paleobasinward down depositional dip; and, along depositional strike, they exhibit bidirectional, concave-upward dips if the delta-front was lobate in plan view (e.g., Willis et al.;<ref name=Wllsetal1999 /> Kolla et al.;<ref name=Kll>Kolla, V., P. Biondi, B. Long, and R. Fillon, 2000, Sequence stratigraphy and architecture of the late Pleistocene Lagniappe delta complex, northeast Gulf of Mexico, inD. Hunt, and R. L. Gawthorpe, eds., Sedimentary responses to forced regressions: Geological Society, London, Special Publication 172, p. 291–327.</ref> Roberts et al.<ref name=Rbrts2004 />) or appear horizontal if the shoreline was approximately linear (e.g., Hampson<ref name=Hmpsn2000 />). Clinoforms are usually truncated at their tops by a variety of channelized erosion surfaces formed during shoreline advance (e.g., distributary channels, incised valleys) and by channelized and/or planar transgressive erosion surfaces (tide and wave ravinement surfaces sense Swift<ref>Swift, D. J., 1968, Coastal erosion and transgressive stratigraphy: Journal of Geology, v. 76, no. 4, p. 444–456, doi: 10.1086/jg.1968.76.issue-4.</ref>) associated with shoreline retreat. Consequently, most sandy shoreline clinoforms lack a decrease in depositional dip (rollover) near their tops, although this geometry is ubiquitous in larger, shelf-slope margin clinoforms (e.g., Steckler et al.<ref name=Stcklr1999>Steckler, M. S., G. S. Mountain, K. G. Miller, and N. Christie-Blick, 1999, Reconstruction of tertiary progradation and clinoform development on the New Jersey passive margin by 2D backstripping: Marine Geology, v. 154, no. 1–4, p. 399–420, doi: 10.1016/S0025-3227(98)00126-1.</ref>) and in the outer, muddy portion of compound deltaic clinoforms with a broad subaqueous topset that lies seaward of the shoreline (e.g., Pirmez et al.<ref>Pirmez, C., L. F. Pratson, and M. S. Steckler, 1998, Clinoform development by advection-diffusion of suspended sediment; modeling and comparison to natural systems: Journal of Geophysical Research B: Solid Earth and Planets, v. 103, p. 24,141–24,157, doi: 10.1029/98JB01516.</ref>).

Here, a geometric approach is used to represent the depositional dip cross-section shape of a clinoform with a dimensionless shape function, ''s(r_c)'' ([[:File:BLTN13190fig2.jpg|Figure 2E]]), such as a power law for concave-upward, sandy, shoreline clinoforms:  

Here, a geometric approach is used to represent the depositional dip cross-section shape of a clinoform with a dimensionless shape function, ''s(r_c)'' ([[:File:BLTN13190fig2.jpg|Figure 2E]]), such as a power law for concave-upward, sandy, shoreline clinoforms: