The nature and age of Cenozoic contractional deformation within the NE Faroe–Shetland Basin

Abstract

A number of large, mainly NE-trending, and a few NNE-trending, Cenozoic to Recent anticlines have been identified from commercial seismic reflection data within the NE Faroe–Shetland Basin. Regional seismic markers have enabled the timing of formation of these structures to be ascertained and they appear to have developed mainly during early to mid-Miocene times, but there is also some evidence of activity through to early Pliocene to Recent, and even of pre-Miocene activity. The ages of the Cenozoic folds within the NE Faroe–Shetland Basin partly overlap with those observed on the Norwegian margin and around the Faroe Islands and the Hatton-Rockall areas, although in general, these regions have an important older component of development. Mechanisms for the formation of the folds are controversial, though results from this study indicate that the NE orientations of many of the folds in the NE Faroe–Shetland Basin are compatible with compression approximately orthogonal to the continental margin. The change from NE- to NNE-trending anticlines in the vicinity of the Magnus and Erlend lineaments/transfer zones may suggest that the development of these folds was related to sinistral strike-slip movement along these major structures. Speculatively, Quaternary strike-slip movement along these zones may also have triggered significant slope failure and the formation of mud volcanoes and mud intrusions as evidenced by the close spatial association of the Miller Slide Headwall and the ‘Pilot Whale Diapirs’.