Predictive Stratigraphic Methods and Their Development: New Global Geological Concepts Driven by Technology Advances
The understanding that the stratigraphic record is not continuous but divided by unconformities and hiatuses goes back to the 19th century. Work in the early and middle parts of the 20th century led to a more consistent and systematic approach. Eustasy and tectonics were introduced as the primary external forcing factors. A further development was time stratigraphy, and this development was critical to introduce predictive ability and to move from static to dynamic stratigraphy. Yet, the advances were based on outcrops, critical to get first-hand knowledge of rocks and stratigraphy, but difficult to test at basin scale. Later predictive stratigraphic methods have largely followed geophysical technology advances without the restrictions outcrops provide in terms of scale and correlability. With the advent of 2D seismic in the 1960's, the ability to view and analyze stratigraphic patters at basin scale came. This provided opportunities to view the linkage between e.g. unconformities (i.e. sequence boundaries) and resulting depositional patterns in basins. As the need and possibility to populate and integrate the seismic with rock data came, and more data became available, sequence stratigraphy resulted. 3D seismic in offshore basins came in full force in the late 1980s early 1990s, and the first surveys on deep-water continental margins revealed detailed sedimentary stratigraphy hitherto not seen and sequence stratigraphy moved to deep-water settings. With high-resolution remote sensing and computer advances came an ability to integrate onshore and offshore data in quantitative ways. A new trend of predictive stratigraphy developed – source-to-sink (S2S) relying on predictive relationships between segments using morphological as well as stratigraphic data. S2S also couples areas of sediment generation with areas of deposition, adding to seismic and sequence stratigraphy that focus on the sink or depositional area. In the last few years, in basins with massive amounts of 3D data, it is now possible to analyze complete S2S systems with catchment, shelf, slope and basin floor segments preserved in merged seismic datasets. This allows for quantitative analysis in a detail not possible before. Still, the challenge exists to confidently populate the seismic with rock data to be fully predictive and take the full S2S system understanding from the subsurface back to the outcrops. Then, the predictive stratigraphic analytical methods will have come full circle.
AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017