Changes

==Sequence boundaries==

==Sequence boundaries==

A depositional sequence is bounded by unconformities or the correlative conformities and is subdivided by internal surfaces of transgression and maximum flooding;<ref name=ch04r68>Mitchum, R., M., Jr., 1977, Seismic stratigraphy and global changes in sea level, II: [[Glossary]] of terms used in seismic stratigraphy, in Seismic Stratigraphy—Applications in Hydrocarbon Exploration: AAPG Memoir 26, p. 205–212.</ref> see also .<ref name=ch04r99>Vail, P., R., 1987, Seismic stratigraphy interpretation procedure, in Bally, A., W., ed., Atlas of Seismic Stratigraphy: AAPG, p. 1–10.</ref><ref name=ch04r79>Posamentier, H., W., Vail, P., R., 1988, Eustatic controls on clastic deposition II—sequence and systems tract models: SEPM Special Publication 42, p. 125–154.</ref><ref name=ch04r70>Mitchum, R., M., Jr., Van Wagoner, J., C., 1990, High-frequency sequences and eustatic cycles in the Gulf of Mexico basin: Proceedings, Gulf Coast Section SEPM 11th Annual Research conference, p. 257–267.</ref> Each of these surfaces is chronostratigraphically significant, separating consistently older strata from younger strata.

A depositional sequence is bounded by unconformities or the correlative conformities and is subdivided by internal surfaces of transgression and maximum flooding;<ref name=ch04r68>Mitchum, R., M., Jr., 1977, Seismic stratigraphy and global changes in sea level, II: [[Glossary]] of terms used in seismic stratigraphy, in Seismic Stratigraphy—Applications in Hydrocarbon Exploration: AAPG Memoir 26, p. 205–212.</ref> see also .<ref name=ch04r99>Vail, P., R., 1987, [http://archives.datapages.com/data/specpubs/oversiz2/data/a188/a188/0001/0000/0001.htm Seismic stratigraphy interpretation procedure], in Bally, A., W., ed., Atlas of Seismic Stratigraphy: [http://store.aapg.org/detail.aspx?id=478 AAPG Studies in Geology No. 27], p. 1–10.</ref><ref name=ch04r79>Posamentier, H., W., Vail, P., R., 1988, Eustatic controls on clastic deposition II—sequence and systems tract models: SEPM Special Publication 42, p. 125–154.</ref><ref name=ch04r70>Mitchum, R., M., Jr., Van Wagoner, J., C., 1990, High-frequency sequences and eustatic cycles in the Gulf of Mexico basin: Proceedings, Gulf Coast Section SEPM 11th Annual Research conference, p. 257–267.</ref> Each of these surfaces is chronostratigraphically significant, separating consistently older strata from younger strata.

An alternative concept of defining a depositional sequence is that of Galloway.<ref name=ch04r34>Galloway, W., E., 1989a, Genetic stratigraphic sequences in basin analysis I: architecture and genesis of flooding-surface bounded depositional units: AAPG Bulletin, vol. 73, p. 125–142.</ref><ref name=ch04r35>Galloway, W., E., 1989b, Genetic stratigraphic sequences in basin analysis II: application to northwest Gulf of Mexico Cenozoic basin: AAPG Bulletin, vol. 73, p. 143–154.</ref> Galloway uses the maximum flooding surface and correlative condensed section as the bounding surface of the “genetic” depositional sequence. Both sequence concepts use the erosional unconformities, maximum flooding surface, and transgressive surface as interpretation horizons for partitioning each sequence. Sequence surfaces are often best recognized on seismic reflection profiles by stratal terminations called ''lapouts'', such as downlap and onlap.

An alternative concept of defining a depositional sequence is that of Galloway.<ref name=ch04r34>Galloway, W., E., 1989a, Genetic stratigraphic sequences in basin analysis I: architecture and genesis of flooding-surface bounded depositional units: AAPG Bulletin, vol. 73, p. 125–142.</ref><ref name=ch04r35>Galloway, W., E., 1989b, Genetic stratigraphic sequences in basin analysis II: application to northwest Gulf of Mexico Cenozoic basin: AAPG Bulletin, vol. 73, p. 143–154.</ref> Galloway uses the maximum flooding surface and correlative condensed section as the bounding surface of the “genetic” depositional sequence. Both sequence concepts use the erosional unconformities, maximum flooding surface, and transgressive surface as interpretation horizons for partitioning each sequence. Sequence surfaces are often best recognized on seismic reflection profiles by stratal terminations called ''lapouts'', such as downlap and onlap.