CONTINENTAL SEQUENCE STRATIGRAPHIC METHODS WITH EMPHASIS ON CONTINENTAL CARBONATES

Sequence stratigraphy provides an excellent foundation for correlation, interpretation, and predictive stratal modeling of continental strata. There are three basic surfaces suitable for bounding units in continental sequence stratigraphy. These surfaces are the subaerial unconformity, the maximum flooding surface, and the correlative conformity. Other sequence stratigraphic terminology such as systems tract and parasequence can be utilized in continental sequence stratigraphy, but they may be more applicable to certain depositional environments that mimic marine processes such as lacustrine settings.

Continental carbonates are invaluable for use in sequence stratigraphic studies because they are often the most practical marker beds to use for delineating sequence boundaries. Calcic paleosols and pedogenically modified palustrine deposits are the most commonly used carbonates for sequence boundary delineation. These units are frequently associated with regional surfaces and their physical properties make them easily identifiable on the surface and in the subsurface.

Controls on the formation of continental carbonates within a sequence stratigraphic framework are varied and are often interrelated. Primary controls are tectonism and climate. Eustasy may play a major role in coastal-plain settings. Difficulties in isolating climate from tectonism arise because climate is certainly a controlling factor on carbonate precipitation, whereas tectonics can control accommodation space for sedimentation. Nonetheless, regional tectonic/climatic settings as well as local geologic features linked with carbonate-delineated sequences can help to determine a primary control on sequence and sequence-boundary formation.