Computer Simulation Model of Clastic Sedimentary Processes
Daniel M. Tetzlaff
This paper describes a computer model, SEDSIM I, that simulates erosion, transport, and deposition of clastic sediments by free-surface flow in natural environments. The model is essentially deterministic, and is based on physical laws of flow and sediment transport. It is applicable to a large variety of sedimentary systems, including rivers, deltas, submarine canyons, and turbidite fans. Extensive computer graphics are used to display the three-dimensional geometry of the simulated deposits.
Using SEDSIM I is similar to performing physical sedimentation experiments in a laboratory, without the space and time scaling limitations encountered in the laboratory. Initial conditions given to the program consist of a topographic grid, locations of sources of fluid and sediment, physical parameters of up to four arbitrary sediment types, and a few other variables. The program employs a "particle-cell" numerical method that can simulate both steady or unsteady flow. Within certain limits, imposed mainly by the amount of computer power available, the model performs realistically, even in processes involving channel shifting, and vast topographic changes occurring over periods of geologic time. Results can be displayed as a changing succession of topographic contour maps, perspectiv diagrams (including stereographic pairs), current velocity plots, and vertical cross sections showing sediment age and composition.
The model is compared to known modern environments. Many application examples are presented. Simulation models based on this approach can become useful tools in investigating modern as well as ancient clastic systems.
AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.