Julian Thorne

Simulation of sedimentary facies on the Northern California Shelf

A dynamic model is developed to simulate the sedimentary facies on the Northern California Shelf. In the model, dispersal mechanisms of small time scale are described by deterministic sediment-transport equations. However, at large time scale, the shelf dispersal system is described in probabilistic terms owing to its stochastic behavior. The probability of storm-bed generation is described by the bed generation potential, P g , which is determined by the probability density distribution function of the local storms. The bed preservation potential, P p , valued between 0 and 1, is a parameter that describes the probable truncation a storm bed that will be buried in a bed succession. The truncation depends on the erosion and deposition caused by subsequent random storms. By estimating the preservation potentials of all generated storm beds, the most probable storm-bed succession is predicted. The computations support the hypothesis that sedimentary facies are produced by the coupled mechanisms of progressive sorting and stratal condensation on continental margins.