The papers contained on this CD mostly originate from a session at the 2002 Annual Meeting of the Canadian Society of Petroleum Geologists, repeated at the 2004 Dallas AAPG Meeting. The theme of both sessions was “Facies Models Revisited”, to see what sort of progress had been made since the third (1992) edition of Facies Models, published by the Geological Society of Canada.
During the ten years between 1992 and 2002, there has been considerable progress in the understanding of modern and ancient depositional environments. This additional complexity makes modeling much more difficult, and raises the problem of whether modeling still serves a purpose. The original reasons for creating facies models still exist—a model is a point of comparison, it is a guide for further observations, it serves as a basis for hydrodynamic interpretation, and most importantly, it acts as a predictor in new situations.
Using submarine fans as an example, it is clear that progress during the last ten years (particularly in 3-D seismic) has highlighted the inadequacy of all pre-existing models—indeed, no comprehensive models have been proposed since the mid eighties. Yet with continued and increasing exploration in submarine fan systems, predictive models are even more necessary. The traditional approach, of distilling the features that modern and ancient systems have in common, is extremely difficult (and probably naive) in such diverse and complex systems. Instead, it is necessary to identify all of the constituent building blocks of submarine fans (channels, point bars, levees, splays, frontal lobes and so on), and try to identify the salient features of each. New models for particular situations can be constructed by examining the relationships of the constituent building blocks. For example, sinuous channels, levees and splays may be closely related in space, whereas frontal lobes are unlikely to be related to sinuous leveed channels (except for the channel that ultimately feeds the lobe). A three-dimensional reconstruction can therefore be made by examining the building blocks that are closely and commonly related, and also using information from the building blocks that are seldom or never found in juxtaposition.
These principles, discussed above for submarine fans, can be applied to all depositional environments, at all scales. The ideas are elaborated in this introductory paper, and can be seen in the other contributions to this CD.