Mechanisms of overburden deformation associated with the emplacemenet of the Tulipan Sill, Mid-Norwegian Margin

Abstract

Accounting for i gneous intrusion s in to sedimentary basins is important to the petroleum industry because magmatism deforms the host rock and affects the thermal evolution of a basin, thereby influencing hydrocarbon generation, migration, and accumulation. Presently, numerous mechanisms concerning the syn - emplacement (i.e. elastic bending related active uplift and aureole induced volume reduction) and post - emplacement (i.e. differential compaction) deformation of the host rock have been suggested . In this study, we investigate the relevance of the different existing syn - or post - emplacement related mechanical models of dome growth accommodating the emplacement of igneous sills. We us e hi gh - quality 3D seismic and well data located in the western part of the Møre Basin (mid - Norwegian margin) to analyze the deformation of Cretaceous – Paleogene overburden associated with the emplacement of the Tulipan saucer - shaped sill between 55.8 and 54.9 Ma . H orizon interpretation s and various thickness and attribut e maps show a clear correlation between the saucer - shaped Tulipan sill and an observed domed structure above. Additional l y , we observe in the shallow parts of the dome structure hydrothermal ve nt complexes connected by fractures only along the periphery of the underlying sill. We show that the Tulipan sill is responsible for the dome structure in the overburden of the study area. At the same time we see that not solely one of the different mecha nisms of overburden deformation can be responsible for the observed dome structure , but the combination of them.