3D Facies Model in Large-scale Fan Delta Complexes (Montserrat and Sant Llorenç del Munt, Eocene, Ebro Basin, NE Spain)

Abstract

An exploration scale facies model (375 km2 and 325 m thick) of two outcropping fan-delta complexes developed during the Eocene in the SE Ebro basin margin was produced. Input data for the model comprises detailed geological maps. This model satisfactorily captures the heterogeneity linked to the T-R cyclicity at two scales. The transgressive and regressive organization of coastal facies belts (at scale of sequence sets and composite sequences) was achieved by the reconstruction of key surfaces and modelling facies belt boundaries in between by using the linear expectation trend of TTG algorithm. The position of these facies boundaries was fixed on the basis of paleogeographic maps extracted from detailed field mapping. Due to its small scale expression, high frequency cyclicity (fundamental sequences) was addressed by the stochastic part of the TTG algorithm. The model reproduces a continuous delta front facies belt connected along the different sequences. However, its complex geometry also capture the existence of potential stratigraphic traps related to the endings of fan-delta front reservoir analogue facies wedges into prodelta and distal alluvial mudstones resulting from the T-R cycles at composite sequence scale.