Characterisation and development of Early Cretaceous shelf platform deposition and faulting in the Hoop area, southwestern Barents Sea—constrained by high-resolution seismic data

Abstract

Regional Early Cretaceous uplift of the northern Barents Sea associated with the High Arctic Large Igneous Province (HALIP) caused the development of the fluvial to open-marine depositional system, terminating in the southwestern Barents Sea. This study has established a new temporal and spatial evolution of the Lower Cretaceous deposits in the Hoop area, in particular the location and age of the intrashelf platform lobe front and subsequent block-faulting. A composite high-resolution 3D and 2.5D P-Cable and conventional 3D seismic dataset image the strata and cross-cutting faults in the Hoop area. The P-Cable data typically have a resolution of 3–7 m in the shallow subsurface, up to four times better than the conventional seismic data, contributing to a new and better mapping hence understanding of the Lower Cretaceous strata and faults. Seismic horizon and facies mapping reveal large-scale clinoforms, with present-day heights of 150–200 m and dips of 0.65–1.13°. The highresolution data furthermore display complex stratigraphic and structural features, such as small-scale clinoforms and numerous faults. The shelf platform succession is block-faulted, and the main Early Cretaceous fault activity thus postdates the arrival of the delta and platform sediments from the northwest. Detailed seismo-stratigraphic ties to the 7324/2–1 (Apollo) and 7325/1–1 (Atlantis) wells, and ties to the adjacent Fingerdjupet Subbasin, document a Barremian age for the shelf platform deposits and an Aptian?–early Albian age for the main faulting event. The faulting was likely initiated in the Aptian, but a hiatus or condensed section above the Barremian strata makes it difficult to constrain the onset of deformation in the Hoop area.