P. R. Vail, 1977. "Seismic Recognition of Depositional Facies on Slopes and Rises", Geology of Continental Margins, Joseph R. Curray, William R. Dickinson, Wallace G. Dow, Kenneth O. Emery, Donald R. Seely, Peter R. Vail, Hunter Yarborough
Download citation file:
The depositional facies on slopes and rises depend in large part on the tectonic processes and sea level changes, as well as rate and type of sediment supply. Seismic examples of slope and rise depositional facies from divergent, convergent, and strike-slip continental margins are presented and discussed in terms of sea level changes and sediment supply.
Seismic sequence and seismic facies analyses are effective methods for recognition of depositional facies on slopes and rises and studying the interrelationships between tectonic processes, sea level changes, and sediment supply. Seismic sequence analysis is based on the identification of stratigraphic units composed of a relatively conformable succession of genetically related strata termed depositional sequences, Fig. 1. The upper and lower boundaries of depositional sequences are unconformities or their correlative conformities. The time interval represented by strata of a given sequence may differ from place to place, but the range is confined to synchronous limits marked by ages of the sequence boundaries where they become conformities. Depositional sequence boundaries are recognized on seismic data by identifying reflections caused by lateral terminations of strata termed onlap, downlap, toplap, and truncation, Fig. 1. The depositional sequences, because they consist of genetically related strata having Chronographic significance, provide an ideal stratigraphic interval for seismic facies analysis. Seismic facies analysis is the deliniation and interpretation of reflection geometry, continuity, amplitude, frequence, and interval velocity, as well as the external form and associations of seismic facies units. Once the seismic facies parameters are described and mapped, an interpretation of
Figures & Tables
Geology of Continental Margins
Written in 1977 the publication presents interpretations of then-new data bearing on the geology and geophysics of continental margins. The book includes a discussion of plate tectonics and evolution of continental margins; presentations on the stratigraphy and structure of pull-apart and compressional margin;, prospective petroleum source rocks, their organic content, rate of burial, and distribution on slopes and rises of different margin types; prospective reservoir rock patterns in relation to depositional processes and to the sedimentary and structural histories for different types of continental margins; and seismic recognition of depositional facies on slopes and rises for different margin types with varying rates of sediment supply during eustatic sea-level changes.