Shelf edge and shoreline trajectories, a dynamic approach to stratigraphic analysis

The Shelf Edge and Shoreline Trajectories Conference, convened in Tromso, Norway, during the autumn of 2007, was attended by a group of specialists working in the crossover between industry and academia. This paper introduces the concepts of shelf edge-and shoreline-trajectory analysis, and discusses some of the advantages of applying such concepts in contrast to more traditional sequence stratigraphic analysis. This special issue of Basin Research focuses on how observations of outcrop and subsurface datasets, particularly three-dimensional (3D) seismic data, may be used as an aid to identify palaeo-shelf edges and shorelines. Moreover, the approach shows how linking the cross-sectional path of a shoreline as it migrates (shoreline trajectory) and the pathway taken by the shelf-edge during the development of a series of accreting clinoforms (shelf-edge trajectory) to the analysis of sedimentological or seismic facies can improve predictions of lithology distribution. The following 15 papers present well-documented case studies from a variety of shelf and shelf-margin settings where these concepts have been applied to depositional systems ranging in age from Permian to Recent. A wide spectrum of data types and methods, including two dimensional and 3D seismic data, well logs and core material as well as high-resolution biostratigraphy, outcrop studies and modern bathymetric data have been applied in the various papers. Despite the considerable age range of the deposits investigated and the data types used for the studies, all of the authors have converged towards the objective approach of trajectory analysis. However, any analytical method has some uncertainty attached to it, and a discussion of possible pitfalls and sources of error is also a part of this introductory paper. Although this special issue presents some recent advances in the way to conduct stratigraphic analysis, we realise that this is only a further step in an evolving discipline. Development of sequence stratigraphic concepts will continue, and new contributions will evaluate past work as they seek to develop the subject.