Future of Sequence Stratigraphy
Ron Steel
Department of Geological Sciences, Jackson School of Geosciences
Ron Steel is Professor and Chair of Department of Geological Sciences, Jackson School, UT Austin and Emeritus Sixth-Century Chair at the University of Aberdeen, Scotland. He was previously Wold Chair of Energy at the University of Wyoming, Chief Geologist at Norsk Hydro, Norway and Professor of Reservoir Geology at University of Bergen Norway and was educated at the University of Glasgow, Scotland. He has some 180 published papers, edited 9 books, received 6 best paper or poster awards, and graduated 140+ MS and PhD students from the universities of Bergen, Wyoming and UT Austin. His current research interests are on the construction of shelves and shelf margins by deltas. He currently has graduate students working on paleo-Orinoco margin of East Venezuela/Trinidad, Jurassic margin of the southern Neuquen Basin Argentina, Wilcox shelf construction in Gulf of Mexico and the paleo-Colorado margin of the early Gulf of California.
Abstract
The Sequence Stratigraphy revolution included Exxon’s key claim of a fundamental and repetitive stratigraphic motif, seen on their global seismic data, which was to become the sea-level driven, stratigraphic ‘sequence’.... [ view full abstract ]
The Sequence Stratigraphy revolution included Exxon’s key claim of a fundamental and repetitive stratigraphic motif, seen on their global seismic data, which was to become the sea-level driven, stratigraphic ‘sequence’. This brought huge value to stratigraphy in terms of (1) emphasizing the need to integrate classical stratigraphy with depositional systems, and so highlighting the dynamic character of the new stratigraphy; (2) providing guidelines and a methodology for deciphering stratigraphy in new regions, particularly emphasizing the need to identify the basic regressive and transgressive components of river-delivered, shelf-transiting systems; and (3) providing the framework for a source-to-sink understanding of stratigraphy, and thereby enables a deciphering of provenance as well as sediment-budget and grain size partitioning across alluvial plain to deepwater transects. The sediment-budget volume partitioning is beginning to bring surprises. A component of this source-to-sink understanding is the predictive power that Exxon originally sought.
Sequence stratigraphy has been much less successful in providing an understanding of the sequence-controlling variables, partly because it was initially tied strongly to sea-level change, and stratal patterns were given sea-level terms. Ironically, just as a great number of stratigraphers (including myself) appeared to reach near-consensus on terminology in 2009, Exxon stratigraphers recanted and suggested that it may have been a mistake to link stratal pattern and sea-level condition. Release from this constraint is now allowing great progress in integrating outcrop, subsurface and experimental studies in dynamic stratigraphy. On margins with a large sediment flux, and especially in Greenhouse times, deepwater fans are now as commonly reported at sea-level highstands as at lowstands, autogenic responses in stratigraphy during steady forcing of external variables are being emphasized and the non-uniqueness of stratigraphic changes and key surface generation is being demonstrated, not least because of modeling and experiments in stratigraphy. These approaches are no longer ‘threatening’ to sequence stratigraphy, but strengthen it.
Session
KN6 » Keynote Lecture (09:30 - Thursday, 25th June, Pangea)
