The Paleogene Central Basin on Spitsbergen is located close to a major intra-plate transform fault zone west of Spitsbergen, and presumably developed as a foreland basin in front of the West Spitsbergen Thrust Belt. The oldest, Paleocene, basin-fill was deposited along the distal margin of the foredeep, with sediment derived from the peripheral bulge area. The overall transgressive succession consists of two transgressive-regressive cycles that in turn consist of numerous, short-duration coastal plain – shoreface – shelf sequences. Sequences forming the transgressive parts of the cycles are thin, sheet-like, and onlap the distal basin-margin, while sequences of the regressive parts are wedge-shaped, basinward-stepping, and associated with regional unconformities along the basin-margin.
We suggest that the transgressive-regressive cycles were largely controlled by peripheral-bulge dynamics with episodic uplift and destruction of the peripheral-bulge. Transgressive phases probably resulted from tectonically ‘quiet’ periods where the basin floor was passively down-warped due to sediment loading, and the peripheral bulge relief became gentler. Regressive phases occurred during periods of loading along the thrust-belt margin, which caused tilting of the distal basin margin in response to uplift and basinward migration of the peripheral bulge.
The behaviour of the peripheral bulge is mainly predicted from models, as the sedimentary record on the distal margin of the foreland basin is commonly dominated by hiati. Well-exposed fieldwork-based examples of a relatively complete clastic, peripheral bulge-derived foredeep succession thus provides a unique opportunity to confirm predicted responses of depositional systems on the distal foreland basin margin to adjustments in the basins flexural profile.
SEPM: Depositional Processes, Facies, and Sequence Stratigraphy in Foreland Basin Settings