Analysis of shelf-edge trajectories in prograding successions from o¡shore Norway, Brazil,Venezuela and West Africa reveals systematic changes in facies associations along the depositional dip.These changes occur in conjunction with the relative sea-level change, sediment supply, inclination of the substratum and the relief of the margin. Flat and ascending trajectories generally result in an accumulation of £uvial and shallow marine sediments in the topset segment. Descending trajectories will generally result in erosion and bypass of the topset segment and deposition of basin £oor fans. An investigation of incised valley ¢lls reveals multiple stages of ¢lling that can be linked to distinct phases of deepwater fan deposition and to the overall evolution of the margin. In the case of high sediment supply, like the Neogene Niger and Orinoco deltas, basin £oor fans may develop systematically even under ascending trajectory styles. In traditional sequence stratigraphic thinking, this would imply the deposition of basin £oor fans during a period of relative sea-level highstand. Facies associations and sequence development also vary along the depositional strike.The width and gradient of the shelf and slope show considerable variations from south to north along the Brazilian continental margin during the Cenozoic. During the same time interval, the continental shelf may display high or low accommodation conditions, and the resulting stacking patterns and facies associations may be utilized to reconstruct palaeogeography and for prediction of lithology. Application of the trajectory concept thus reveals nuances in the rock record that would be lost by the application of traditional sequence stratigraphic work procedures. At the same time, the methodology simpli¢es the interpretation in that less importance is placed on interpretation and labelling of surface boundaries and systems tracts.Given su⁄cient sediment supply and water depths, the basinward progradation of coastal prisms and clastic wedges

Trajectory analysis is an alternative approach to systems tract analysis in unravelling the sequence stratigraphic development of sedimentary successions. Whereas the latter anticipates a succession of the depositional history in terms of a given order of systems tracts, trajectory analysis combines trajectory classes in any order, thus providing a more flexible interpretation of the depositional evolution with fewer a priori assumptions about the type or the nature of the mechanisms driving sequence development. The overall regressive part of the Brent Delta (Middle Jurassic, Northern North Sea) has been analysed using this approach. The distribution, thicknesses and stacking patterns of facies associations have been analysed to unravel the trajectorial behaviour of the system. In proximal areas (Oseberg domain), thin shoreface/foreshore packages associated with a prograding strandplain are overlain by upper delta‐plain (floodplain) and distributary channel deposits. Flat or descending regressive trajectories can explain the stratigraphic development in this area. A short distance to the north (Huldra domain), the presence of thicker shoreface/foreshore packages and lower delta‐plain sediments suggests a low‐angle ascending regressive trajectory. In more distal areas (Gullfaks and Visund domains), a higher rate of aggradation leads to the development of even thicker shoreface/foreshore packages and the development of lagoons and bays in the lower delta‐plain realm. Alternating high‐ and low‐angle ascending regressive trajectories can explain the distal development.

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