Although eolian facies models have been developed since the 1970s, only recently have they become sufficiently sophisticated to enable the effects of external climatic and tectonic controls to be expressed in terms of resultant facies architecture. By using a joint conceptual and process-based approach, the response of eolian systems to changes in controlling parameters such as sediment supply, sediment availability, water table, and wind regime is now well understood. Dynamic facies models are able to account for spatial and temporal variations in these controlling parameters and predict likely stratigraphic responses. Large-scale, quantitative stratigraphic data sets from outcrop are being applied to unequivocally demonstrate relationships between preserved eolian architecture and original bedform morphology and migratory behavior.
In dry eolian systems, the key to developing predictive facies models has been an appreciation of the paleoenvironmental significance of the 3D geometry and hierarchical nature of bounding surfaces, which has enabled the products of external (allocyclic) controls such as climate change be discerned from the complex mechanics of intrinsic (autocyclic) bedform migratory behavior. In wet eolian systems, subtle variations in interdune architecture provide the basis for a spectrum of predictive facies models that explain preserved eolian architecture in terms of interactions between water-table level, sediment availability, dune size, and dune migration rate, parameters which in turn are a function of sediment distribution pathways, climate, and basin setting.
The development of eolian facies models is important for understanding the likely response of desert systems to climatic and environmental change. Additionally, predictive models remain important for hydrocarbon exploration, particularly in mature provinces, where good well control allows the employment of sophisticated models in the search for small plays based on subtle stratigraphic traps.