Björn Nyberg

Assessing First-order BQART Estimates for Ancient Source-to-Sink Mass Budget Calculations: The Sognefjord Source-to-Sink system, Northern North Sea Rift.

Constraining the timing and volume of sediment dispersal in an ancient sedimentary system is vital to understand a basins infill history. In recent years, first-order approximation of ancient sediment load to a basin has relied on empirical observations of modern riverine systems. The empirical relationships apply simplified understanding of hinterland controls such as basin morphology, topography, climate, runoff and bedrock characteristics to observed river sediment loads. Despite the popularity of those methods, a comprehensive assessment on the validity of modern observations to measure sediment load on geological timescales is lacking.  Here we investigate the uncertainties, sensitivities and practicalities surrounding the use of modern empirical observations to evaluate ancient sediment river loads using a case study of the Middle to Late Jurassic Sognefjord source to sink (S2S) system, offshore Norway. Combined with new regional seismic data, the full extent of the shallow-marine siliciclastic successions across the Horda Platform provides a well-constrained sedimentary system to measure unaccounted volume of sediment.