1990. "Parasequence", Siliciclastic Sequence Stratigraphy in Well Logs, Cores, and Outcrops: Concepts for High-Resolution Correlation of Time and Facies, J. C. Van Wagoner, R. M. Mitchum, K. M. Campion, V. D. Rahmanian
Download citation file:
Parasequences have been identified in coastal plain, deltaic, beach, tidal, estuarine, and shelf environments (Van Wagoner, 1985). It is difficult to identify parasequences in fluvial sections where marine or marginal-marine rocks are absent, and in slope or basinal sections, which are deposited too far below sea level to be influenced by an increase in water depth. The general concepts presented her eapply to all of the depositional environments mentioned above in which parasequences have been recognized; the following discussion illustrates deltaic and beach parasequences because these are common in most basins.
Figures & Tables
Siliciclastic Sequence Stratigraphy in Well Logs, Cores, and Outcrops: Concepts for High-Resolution Correlation of Time and Facies
Application of sequence-stratigraphic analysis depends on the recognition of a hierarchy of stratal units including beds, bedsets, parasequences, parasequence sets, and sequences bounded by chronostratigraphically significant surfaces of erosion, nondeposition, or their correlative surfaces. This method of stratigraphic analysis contrasts with the use of transgressive and regressive cycles of strata for regional correlation of time and facies. Transgressive and regressive cycles have been used for regional correlation for at least 50 years. Recently, proponents of transgressive and regressive cycles, referred to as T-R units, for regional correlation have included Ryer (1983), Busch and Rollins (1984), Busch et al. (1985), and Galloway (1989a). Galloway (1989a) introduced the “genetic stratigraphic sequence,” which is a regressive depositional unit bounded by transgressive surfaces. Although he did not define it specifically, he described it as “a package of sediments recording a significant episode of basin-margin outbuilding and basin filling, bounded by periods of widespread basin margin flooding.”