HR: 1330h
AN: OS52A-0888    [PDF]
TI: Numerical Experiments to Investigate how Processes Form Strata.
AU: * Hutton, E W
EM: eric.hutton@colorado.edu
AF: University of Colorado, 1560 30th St., Boulder, CO 80309-0450 United States
AU: Pratson, L F
EM: lincoln.pratson@duke.edu
AF: Duke University, 103 Old Chemistry Bldg., Durham, NC 27708-0230 United States
AU: Syvitski, J P
EM: james.syvitski@colorado.edu
AF: University of Colorado, 1560 30th St., Boulder, CO 80309-0450 United States
AU: Storms, J E
EM: j.e.a.storms@ta.tudelft.nl
AF: Delft University of Technology, P.O. Box 5028, Delft, NL-2600 Netherlands
AB: {\it sedflux}$_{2D}$ is a numerical model that is able to simulate the deposition and erosion of sediment within a basin over geologic time scales. For this paper, we use an upgraded {\it sedflux}$_{2D}$ to examine the importance of physical processes on both the evolving stratigraphy as well as the final stratigraphy. We have upgraded {\it sedflux}$_{2D}$ by including a near-shore shelf reworking module (Storms, 2003), and a fluvial erosion/deposition module (Paola, 1992). We are able to analyze the output of this numerical model to precisely reconstruct the basin evolution. That is, we know where and when specific processes lay down strata. Furthermore, we can reconstruct strata that were eroded and so are no longer present at the end of the simulation. For this paper we have performed a series of numerical experiments using {\it sedflux}$_{2D}$ that examine the effects of various processes. We begin with first order processes such as sea level variations and subsidence. We then begin adding complexity to the simulations by varying sediment supply, and introducing smaller scale processes such as debris flows, turbidity currents, and waves. We note that certain facies are consistently eroded and so do not appear in the final deposit. Specifically, we see that much of the shore-face sediments are missing from the stratigraphic record. Also, we note that these shore-face sands are more likely to be preserved during a transgression. Principally, this is due to increased erosion by the river during falling sea level. On the other hand, ocean storms are efficient at eroding shallow marine sediment during either rising or falling sea level. It is the combination of these two processes that conspire to remove much of the stratigraphic signature of the shore-face.
DE: 4255 Numerical modeling
DE: 4558 Sediment transport
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting