Depositional environments of the Early to Middle Triassic northern North Sea in a syn-rift to a post-rift setting

Abstract

Abstract In the northern North Sea, the Early to Middle Triassic Teist and Lomvi formations (Induan–Landinian age) have received little attention and have historically been of limited interest for exploration. The northern North Sea has now become a mature hydrocarbon province in demand of new exploration targets and these Triassic formations may extend its lifetime. The Triassic succession was influenced by the Permo-Triassic rift-phase and experienced a climatic change from arid and desert environments in the Late Permian to more humid conditions in the Jurassic above. Analysis of cored intervals, petrology of thin sections and wireline log-signatures suggest that the Teist and Lomvi formations range from aeolian sandstones to playa-lake and lacustrine-deltaic depositional environments. The distribution of these different depositional environments shows an association with the Permo-Triassic faults where lacustrine deposits were confined to hanging-wall areas and footwall highs formed areas above the groundwater table allowing aeolian deposits to accumulate. This observation may aid exploration of the under-developed Lomvi Formation.