Incorporating nutrients as a limiting factor in carbonate modelling

Abstract

Nowadays, the use of process-based numerical models to predict facies distribution and stratal architecture constitutes an essential tool in sedimentary basin analysis. One of these models, the SIMSAFADIM-CLASTIC program, simulates clastic transport and sedimentation in three dimensions together with autochthonous marine carbonate production. In this code, carbonate modelling mainly follows predator-prey relationships among species associations based on Lotka-Volterra equations. The carbonate model also considers other environmental factors such as the presence of siliciclastic sediments and carbonate mud in suspension and water depth. Although these parameters are important, carbonate producers are largely conditioned by other variables, which have to be taken into account in order to obtain a more realistic approach. In this contribution, nutrient availability is added as a new limiting environmental parameter, which exerts control over carbonate producing organisms. A synthetic sample experiment is used to show that inclusion of nutrient availability is critical to reproduce carbonate lithofacies heterogeneity in a more accurate temporal and spatial disposition as a function of trophic resources.