ABSTRACT Much of the theory and practice of seismic sequence stratigraphy has never been explicitly described. This report is an analysis of the implicit assumptions behind the methodology of seismic sequence stratigraphy. These assumptions are divided into four groups: (1) seismic stratal geometry identification, (2) the depositional sequence model, (3) the inverse model used to make sequence interpretations of seismic data, and (4) the global correlation model used in construction of the Exxon cycle chart. In a geologic area using a particular set of seismic data, some of these assumptions will be valid and others will be questionable. Focused research on the critical assumptions of the sequence stratigraphic hypothesis should generate an advanced methodology that provides increased-confidence seismic interpretations.

Abstract It was little more than a decade ago (Sheridan, 1974) that it was realized that the sedimentary thickness at the U.S. Atlantic margin was in excess of 10 km, 2 to 3 times the previous estimates of basement depth. In the years that followed, multichannel seismic (MCS) reflection profile data first became available (Schlee and others, 1976), the first deep offshore well was drilled (COST B-2 in March 1976), and industry and academic scientists rapidly increased their knowledge of the margin. Concurrent with the increase in data, the first models of continental margin subsidence (Sleep, 1971; Falvey, 1974; McKenzie, 1978) were developed, and techniques for studying basin subsidence were introduced (Watts and Ryan, 1976; Van Hinte, 1978; Steckler and Watts, 1978). As a result, the U.S. Atlantic margin was one of the first to be subjected to quantitative subsidence analysis, and our present view of passive margin development has been greatly influenced by research at this margin. Thus, it is appropriate that we now assess what has been learned and what information may be obtained from future subsidence studies of this margin.