Application of the Sequence Stratigraphic Approach: Models Versus First Principles

Ole Martinsen¹ and Henry W. Posamentier^2
1 Norsk Hydro Research Centre, Bergen, Norway
² Anadarko Canada Corporation, Calgary, AB

Sequence stratigraphy is an approach to analyzing lithologic successions. It is built on a set of rules based on geologic first principles and involves the ordering of geologic observations within a time stratigraphic framework and the recognition of key bounding surfaces. Consequently, there is no “model” in the classical sense, but rather a set of rules that enables the geoscientist to develop a robust interpretation.

The key to the sequence stratigraphic approach lies in 1) a thorough understanding of geologic first principles, 2) creativity in approaching the data, and 3) flexibility in developing multiple working hypotheses, whether the data set is regional or high resolution. In particular, with high-resolution data sets, which commonly cover smaller areas, discriminating between regionally significant and locally significant surfaces can be difficult. A small “window to the world” will make determination of systems tract difficult. This, however, does not render the approach meaningless; rather it presents new questions that need to be answered.

A case study from the late Pleistocene and Holocene succession of the Varanger Peninsula, northern Norway illustrates this approach. This succession displays an extremely high-resolution sedimentary record deposited over the last 15000 years and shows in an extreme way the importance of understanding first principles in geology for applying sequence stratigraphy. At least three orders of sequences with widely variable geometries can be defined controlled by varying rates of post-glacial isostatic uplift, eustatic rise, shoreface processes, climatic change and rapid changes of sediment supply.