Interactive (SEDPAK) simulation of clastic and carbonate sediments in shelf to basin settings

Abstract

SEDPAK is an interactive computer simulation which erects models of sedimentary geometries by infilling a two-dimensional basin from both sides with a combination of clastic sediment or in situ and transported carbonate sediments. The simulation program is implemented in “C” on an Apollo DN3000 workstation using graphical plotting functions. Data entry, including the initial basin configuration, local tectonic behavior, sealevel curves, amount and source direction of clastic sediment, and the growth rates of carbonates as a function of water depth is performed interactively. The modeled geometries of clastic and carbonate sediments evolve through time and respond to depositional processes that include tectonic movement, eustasy, and sedimentation. Clastic modeling includes sedimentary bypass, erosion, and sedimentation in alluvial and coastal plains, marine shelf, basin slope, and basin floor settings. Carbonate modeling includes progradation, the development of hard grounds, downslope aprons, keep up, catch up, back step, and drowned reef facies as well as lagoonal and epeiric facies. Also included in the model are extensional vertical faulting of the basin, sediment compaction, and isostatic response to sediment loading. Sediment geometries are plotted on a graphics terminal as they are computed, so the user can immediately view the results. Then, based on these observations, parameters can be changed repeatedly and the program rerun until the user is satisfied with the resultant geometry.