DYNAMIC STRATIGRAPHY WORKGROUP

Sediment volume partitioning, topset processes and clinoform architecture – understanding the role of sediment supply, sea level and delta types in shelf margin building and deepwater sand bypass: the Lance-Fox Hills-Lewis system in S. Wyoming

 

People:

Cristian Carvajal, Ron Steel

 

Research question(s):

How do sediment supply, sea level, and deltaic processes interact on a shelf margin setting to control margin accretion and bypass of sediment to deepwater? This problem has significant implications for tectono-stratigraphic models as well as for prediction of relative storage of reservoir sands on the topset, slope, and basin-floor segments of basin infill.

 

Summary of work:

The Maastrichtian Lance-Fox Hills-Lewis shelf margin of the Laramide Washakie-Great Divide Basin (Wyoming) was studied using a large integrated well-log/outcrop dataset. Interpretation of shelf-margin clinothems and detailed volumetric analysis of sediment partitioning across the shelf margin revealed that the margin rapidly filled the basin and that sediment supply was the most significant driver to accomplish this as well as delivering large volumes of sand to the basin floor, even during highstand conditions. High sediment supply was the result of Laramide thrust-driven mountain uplift.

 

Publications and presentations: 

Publications:

Carvajal, C., and Steel, R.J., 2009, Shelf-edge architecture and bypass of sand to deepwater: influence of sediment supply, sea level, and shelf-edge processes: Journal of Sedimentary Research, v. 79, p. 652-672, doi: 10.2110/jsr.2009.059.

Steel, R.J., Carvajal, C., Petter, A., and Uroza, C., 2008, Shelf and shelf-margin growth in scenarios of rising and falling sea level, Hampson, G.J., Steel, R.J., Burgess, P.M., and Dalrymple, R.W., eds., Recent Advances in Models of Siliciclastic Shallow-Marine Stratigraphy: SEPM (Society for Sedimentary Geology) Special Publication 90, p. 47-71.

Carvajal, C., and Steel, R.J., 2006, Thick turbidite successions from supply-dominated shelves during sea-level highstand: Geology, v. 34, p. 665-668.

 

Conference/meeting presentations: