Changes

==Superimposition of phases==

==Superimposition of phases==

[[file:sedimentary-basin-analysis_fig4-34.png|300px|thumb|{{figure number|1}}. Copyright: Haq et al. (1988); courtesy SEPM.]]

[[file:sedimentary-basin-analysis_fig4-34.png|300px|thumb|{{figure number|1}}Amplification of transgressive and regressive cyclicity when superimposed across a continental margin. Copyright: Haq et al.;<ref name=ch04r43 /> courtesy SEPM.]]

When each scale of cyclicity is convolved with or superimposed onto the next higher order, the patterns of transgression vs. regression either amplify or dampen the transgressions and regressions of the next higher order(s) of cyclicity. The right side of the following schematic illustrates cycle stacking of three orders of symmetrical cyclicity of short (narrow curve), intermediate, and long duration (wide curve), analogous to the fourth, third, and second orders of Haq et al..<ref name=ch04r43>Haq, B., Hardenbol, J., Vail, P., R., 1988, Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change: SEPM Special Publication 42, p. 71–108.</ref> Transgressive phases (darker shading) of the short-duration cycles are amplified when coincident with the transgressive phase of the intermediate-duration cycle—even more so if coincident with the transgressive phase of the long-duration cycle.

When each scale of cyclicity is convolved with or superimposed onto the next higher order, the patterns of transgression vs. regression either amplify or dampen the transgressions and regressions of the next higher order(s) of cyclicity. The right side of the following schematic illustrates cycle stacking of three orders of symmetrical cyclicity of short (narrow curve), intermediate, and long duration (wide curve), analogous to the fourth, third, and second orders of Haq et al.<ref name=ch04r43>Haq, B., Hardenbol, J., Vail, P., R., 1988, Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change: SEPM Special Publication 42, p. 71–108.</ref> Transgressive phases (darker shading) of the short-duration cycles are amplified when coincident with the transgressive phase of the intermediate-duration cycle—even more so if coincident with the transgressive phase of the long-duration cycle.

The same pattern of amplification occurs for coincident regressive cycle phases (lighter shading). When short-duration transgressive phases occur on the regressive phase of the intermediate cycle, the short-duration transgressive phase is dampened and will be even more so if it occurs during the long-duration regressive phase. Regressive phases are similarly dampened if they occur on long-duration transgressions.

The same pattern of amplification occurs for coincident regressive cycle phases (lighter shading). When short-duration transgressive phases occur on the regressive phase of the intermediate cycle, the short-duration transgressive phase is dampened and will be even more so if it occurs during the long-duration regressive phase. Regressive phases are similarly dampened if they occur on long-duration transgressions.