DYNAMIC STRATIGRAPHY WORKGROUP
Ronald J. Steel
Professor and Davis Centennial Chair
Office Phone: (512) 471 0954
Fax: (512) 471-9425
Mailing Address: University of Texas at Austin, Department of Geological Sciences, 1 University Station, C1100, Austin, TX 78712
Ron Steel is Professor and Davis Centennial Chair at UT Austin and Sixth-Century Chair of Sedimentary Geology at University of Aberdeen, Scotland. He was previously Lead Sedimentologist and Chief Geologist for Norsk Hydro (1982-90), Professor of Reservoir Geology at the University of Bergen (1990-95) and Wold Chair of Energy at the University of Wyoming (1995-2003). He has >150 published papers and graduated >100 MS and PhD students from the universities of Bergen, Wyoming and UT Austin. He has held Distinguished and Endowed Lectureships for AAPG, Japan Society for Promotion of Science, and University of Texas at Austin.
The main focus of my research over the last 10 years or so, has been to gain an understanding of the time scales, sediment delivery mechanisms, sediment budget partitioning and growth styles of shelves and shelf margins of deepwater basins (RioMAR projects). The following research is done in collaboration with many other scientists and students:
Numerical modeling has shown that deltaic shelf-transit times are generally shorter (10s to 100ky) than believed, implying that fundamental stratigraphic sequences are generally of shorter time scale than conventionally assumed (Muto and Steel 2002); The same modeling has shown that sediment delivery systems (mainly deltas) are able to reach their shelf edge (staging area for deepwater sand release) either by being supply driven or by being accommodation driven (relative fall of sea level). This is important for understanding shelf margins in Greenhouse and Icehouse climates, with their differing eustatic amplitudes and frequencies (Porebski & Steel 2006; Carvajal and Steel 2006).
Scenarios of along-strike, shelf-break variability (Olariu & Steel 2009) and models of shelf-edge deltas, as well as patterns of shelf growth and styles of shelf-margin architecture (Steel et al 2008) are being developed and are the subject of ongoing research (see individual current projects) with the RioMAR consortium.
A new stratigraphic theory, Autostratigraphy, emphasizing self-organisation within sedimentary systems, has been outlined, and proposes that we should account for changes in stratigraphy by autogenic mechanisms (responses that occur with steady external forcing ) as much as possible, before resorting to explanations using unsteady forcing of the external variables (sea level, tectonics, etc.). (Muto and Steel 1997, Muto et al 2007).
Hyperpycnal flow, highly sediment-concentrated river flows during flood, on the shelf and near the shelf edge, is proposed as a major mechanism for creating sustained-flow turbidity currents, complementing the conventional mechanism of slumping (surge-type Bouma turbidites). The theory of this type of flow has long been known, but the characteristics of these flows are now being documented (Plink-Bjorklund et al 2004; Petter and Steel 2006, Olariu et al 2010)
Models of Source-to-Sink sediment budget partitioning, for basins with and without shelf-slope break have been proposed. In shallow-water basins the transgressive sediment volumes increase landwards (before eventually thinning) and are greater than usually assumed. In deepwater basins with <1000m water, the sediment volume preserved in shelf and slope segments is commonly two-thirds of the total, though this varies with the growth trajectory of the shelf break (Carvajal et al 2009 and Gomez-Veroiza & Steel, AAPG in press ).
In addition, my interests in Sedimentation and Tectonics continue, with several students having recently completed research on long, Late Cretaceous transects from the Sevier fold-and-thrust belt out for 100s of km into the Foreland Basin. I am also strongly engaged in understanding relationships between sea-level change and tides, and in particular in developing models of tidal dunes and bars on deltas, estuaries and shelves (BITE project).
Jackson School of Geosciences faculty profile for Ron Steel: