High-resolution sediment mass-budget of the Shetland Platform during the Paleocene–Early Eocene; constraints on external forcing by uplift and climate

Abstract

In the Palaeocene – Early Eocene, distinct surface and stratigraphic signals recorded around Shetland have been correlated to hinterland uplift associated with the Icelandic Plume, the effects of the Palaeocene-Eocene Thermal Maximum and the opening of the Northeast Atlantic Ocean. In this paper, we use a large dataset combining >230,000 km² of 3D and 2D seismic data and >1700 wells to perform a high-resolution analysis of the sediment fluxes and palaeogeographical evolution around Shetland, comparing these results to an empirical-statistical model of sediment generation (BQART equation) to obtain a sediment mass-budget. In the Faroe-Shetland and Northern North Sea basins, two peaks in sediment fluxes are observed: one during the deposition of the Vaila and Lista formations (Selandian – Early Thanetian) and one associated with the Dornoch and Flett formations (close to the Palaeocene – Eocene transition). Comparing these peaks to a set of independent observations suggests that both are likely controlled by uplift, with an exceptional match with various constraints on vertical motions during the Palaeocene – Eocene transition. Each peak in sediment supply has distinct implications for models of geodynamic evolution. Additionally, both long-term and sharp warming during the Palaeocene – Eocene transition appear not to be required to produce the observed sediment supply rates.