Sorry to Intrude, but is it time to checkout of the “Motel Theory” in the Faroe-Shetland?

One area where understanding the critical moment of a petroleum system is challenging is the Faroe-Shetland Basin (FSB). Most basin models invoke oil generation beginning in the mid-Cretaceous at ca.100 Ma, predating deposition of Paleogene reservoirs. This time discrepancy has previously been explained by re-migration from intermediary accumulations (“Motel” hypothesis) and/or overpressure retardation of kerogen maturation. The FSB is characterized by thick Cretaceous stratigraphic packages (up to 5 km) which includes a large proportion (up to 2 km) of Paleogene igneous material. Separating sedimentary and igneous material and adding the igneous material at the correct time between ca.58-55 Ma shallows the modelled burial depth of the Upper Jurassic source rocks during the Cretaceous sufficiently to delay maturation by 17 Myr in comparison to previous studies. Additionally, previous studies have invoked crustal radiogenic heat production (RHP) based on Phanerozoic crust averaging ca. 2.8 μW/m3 in the North Sea (300 km to the east). However, the FSB is underlain by significantly older, colder Neoarchean orthogneisses (ca.2.7 – 2.9 Ga), reducing RHP by up to 50% to ca.1.6 μW/m3 (σ = 0.74). Together our model unifies geological, geochronological and geochemical observations, delaying the onset of petroleum expulsion by up to 40 Myr.