Structure and seismic stratigraphy of the innermost mid-Norwegian continental shelf: an example from the Frohavet area

Abstract

The Frohavet Basin, a newly discovered sedimentary basin on the innermost mid-Norwegian continental shelf, occurs in an area 60×20 km and contains a stratal sequence up to 1000 m thick. Dating by ice-transported erratic blocks suggests a Jurassic age. The sequence is preserved in half-grabens downthrown to the north-west, and is cut by numerous faults, some of which are interpreted as syndepositional. The sequence reflects an upward change from continental deposition, with the Frohavet area acting as a local depocentre, to more widespread continental and marine deposition. The predominant sediment transport direction was towards the north-west. The Frohavet sequence was deformed during a phase of extensional tectonism, probably in Late Jurassic—Early Cretaceous times.