Breaking the Rules: Seismic Reflection Data Applied to the Interpretation of Diagenetic Reaction Fronts at Kilometer to Basin Scale

Davies, R. J.¹, J. A. Cartwright², D. Meadows¹ (1) Durham University, Durham, United Kingdom (2) Cardiff University, Cardiff, United Kingdom

Using seismic data to understand chemical diagenetic processes is a new sub-discipline of seismic stratigraphy that has started to emerge in the last decade. The discipline breaks the most fundamental seismic stratigraphic rule that seismic reflections follow time lines. In fact you should disregard most of what you have learnt from the seismic stratigraphic literature and develop new interpretation skills and experience. We introduce the discipline by reviewing a range of seismic reflection relationships at silica reaction fronts from 4 sedimentary basins in the northern hemisphere (North Sakhalin, Møre, Vøring and Faeroe-Shetland Basins). Seismic reflection imaging is providing vital clues as to the chemical and physical processes occurring at reaction front boundaries and leading to an entirely new method for researching some chemical diagenetic processes. The more important research results to date are (a) the discovery of extraordinary kilometre-scale reaction front patterns that develop over large tracts of sedimentary basins and (b) the recognition of the role this diagenetic process may play in a host of other, globally significant, geologic processes such as submarine slope failures, soft sediment deformation and differential compaction.