Source-to-Sink Sediment Budget and Partitioning in a Laramide Deep-Water Basin
Cristian Carvajal, Ron Steel, 2014. "Source-to-Sink Sediment Budget and Partitioning in a Laramide Deep-Water Basin", Sedimentary Basins: Origin, Depositional Histories, and Petroleum Systems, James Pindell, Brian Horn, Norman Rosen, Paul Weimer, Menno Dinkleman, Allen Lowrie, Richard Fillon, James Granath, Lorcan Kennan
Download citation file:
We illustrate how sediment budgets can be used to understand the relationships between tectonics and sedimentation and to estimate the partitioning of sediment in shelf, slope, and basin-floor fan compartments within ancient shelf-margin strata. The studied Lewis-Fox Hills shelf margin represents the early Maastrichtian infill of the Laramide-type Washakie-Great Divide basin of southern Wyoming. The shelf margin shows an evolution in two stages. In Stage 1, the shelf margin is characterized by rising shelf-edge trajectory associated with increasing clinothem volumes, widening marine topsets, and increasing clinoform heights; a relatively large fraction of the sediment budget is stored on the shelf compartment through Stage 1. In Stage 2, the shelf-edge trajectory becomes more progradational and is associated with decreasing clinothem volumes, wide coastal-plain topsets, and stable to decreasing clinoform heights; a larger fraction of the sediment budget is stored within deep-water compartments. We interpret that the evolution from Stage 1 to Stage 2 is driven chiefly by tectonic uplift of the adjacent mountains and associated basin subsidence: increasing in Stage 1 and stable to possibly decreasing in Stage 2. Sediment budget calculations suggests that average sediment supply to the basin was 4-16 × 106 ton/y, yield was within 200-2000 ton/km2/y, and hinterland maximum relief was 1000-3000 m. Integration of sediment budget estimates within source-to-sink evolution represents a powerful tool to build improved tectono-stratigraphic models, and develop predictive models for sediment storage across shelf-margin compartments.