A regional reassessment of the Brent Group, UK sector, North Sea

Abstract

Abstract The deltaic Brent Group sequence consists of three formations. The Rannoch is a shoreface section; the Etive is a barrier facies. The Ness contains three members: the Enrick, representing a marginal marine back barrier environment; the Oich, an organic-rich open lagoonal shale and the Foyers, a largely fluvially-dominated delta-top or coastal plain deposit. During the Bajocian, facies belts rapidly prograded northwards until the northern part of the area was reached. Here progradation stalled and thick delta front sediments were deposited. Shortly before the delta began to retreat, a temporary relative sea-level rise pushed the delta front southwards resulting in the deposition of an intra-Ness barrier. The progradational sequence is underlain by the Aalenian to lowermost Bajocian Broom Formation fan delta and overlain by the transgressive Tarbert sequence of largely Bathonian age.