Incorporating nutrients as a limiting factor in carbonate modelling Roger Clavera-Gispert a, c, ⁎, Ana Carmona b, c , Òscar Gratacós b, c , Raimon Tolosana-Delgado d a Abteilung Geologie, Universität Bayreuth, Universitätstraße, 30 – 95440 Bayreuth, Germany b Departament de Geodinàmica i Geofísica, Universitat de Barcelona, Martí i Franqués, s/n-08028 Barcelona, Spain c Institut de Recerca Geomodels, Martí i Franqués, s/n-08028 Barcelona, Spain d Laboratori d'Enginyeria Marítima, Universitat Politècnica de Catalunya, c/Jordi Girona 1-3-08034 Barcelona, Spain abstract article info Article history: Received 1 August 2011 Received in revised form 12 February 2012 Accepted 14 February 2012 Available online 22 February 2012 Keywords: Forward-model Sedimentary basin Process-based Nutrients Ecological model 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. © 2012 Elsevier B.V. All rights reserved. 1. Introduction The evolution of carbonate systems is controlled by complex inter- action of environmental parameters, such as sediment accommodation, climatic conditions and oceanographic configuration, which determine the type and amount of carbonate production. The growth potential of carbonate producing organisms is limited by their ecological require- ments, which include availability of O 2 and CO 2 , temperature, salinity, irradiance, bathymetry, hydraulic energy and nutrients, among others (e.g., Mutti and Hallock, 2003). Understanding the dynamics of carbon- ate systems is of utmost importance in ecologic and geologic research as well as in industry, since it improves prediction accuracy in the explora- tion and exploitation of natural resources. However, direct observation of the main processes and controlling factors in the geological record is obviously limited. Therefore, alterna- tive methods must be used in order to determine and quantify them. During the last decades, numerical modelling has become an important tool in the study of geological systems since it permits to test their response by varying the different limiting parameters. Hence, numerical modelling highlights the relationships between controlling factors and the spatial and temporal evolution of geological systems, which can be either past, present or future examples. With this goal, several carbonate modelling programs have been compiled. Some of them simulate two-dimensional carbonate sedi- mentation (Bosence and Waltham, 1990; Bice, 1991; Bosscher and Schlager, 1992; Bosscher and Southam, 1992; Demicco, 1998) or mixed terrigenous-carbonate sedimentation (Komar, 1973; Bitzer and Harbaugh, 1987; Strobel et al., 1989; Hardy et al., 1994; Bitzer, 1999). However, the complexity and spatial distribution of sedimen- tary facies is better represented in three-dimensional models, whether they are focused in carbonate (Burgess and Wright, 2003; Burgess, 2006; Paterson et al., 2006) or in mixed siliciclastic-carbonate systems (Nurdlund, 1999; Quiquerez, et al., 2000; Bitzer and Salas, 2002; Warrlich et al., 2002; Gratacós, 2004; Warrlich et al., 2008; Gratacós et al., 2009a; Hill et al., 2009). In order to obtain a basin-wide chrono-spatial evolution of mixed carbonate-siliciclastic or pure carbonate systems, the forward process- based SIMSAFADIM-CLASTIC program represents a valid approximation (e.g., Gratacós et al., 2009b). This model simulates 3D subaquatic mixed carbonate-siliciclastic transport and sedimentation processes and uses an ecological model, which takes into account associations of organisms, and their capacity to produce carbonate in dependence on water depth and presence of siliciclastic sediments and carbonate mud as well as their relationship with the environment and among them. For a more ac- curate description of SIMSAFADIM-CLASTIC and its previous versions, the reader is referred to Bitzer and Salas (2001, 2002), Gratacós (2004), Gratacós et al. (2009a, 2009b), Carmona et al. (2010). However, and although these parameters are important, the present version of the program does not contemplate important ecological Palaeogeography, Palaeoclimatology, Palaeoecology 329-330 (2012) 150–157 ⁎ Corresponding author at: Universität Bayreuth, Universitätstraße, 30 – 95440 Bayreuth, Germany. E-mail address: roger@clavera.cat (R. Clavera-Gispert). 0031-0182/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2012.02.025 Contents lists available at SciVerse ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo