Detachment Faulting, Successive Incision and Controls on Supradetachment Basin Formation at the Mid-Norwegian Rifted Margin

• DOI: 10.5194/egusphere-egu21-9481
• Publication Date: 2021-03-04T05:25:27Z
• Authors: Julie Linnéa Sehe...; Per Terje Osmundsen; Gwenn Péron-Pinvidic
• Keywords: Detachment fault

<p>Detachment fault systems recording displacements in the order of 10s to 100s km remain poorly understood compared smaller scale normal faults. The evolutionary models developed for growth and interaction Andersonian-type faults are not fully applicable these large-magnitude systems. Consequently, associated basins - so-called supradetachment still extensional half-graben basins.</p><p>Numerical analogue 2D modelling have shed light on mechanisms footwall back-rotation during progressive extension (rolling hinge model; e.g. Lavier et al., 1999) but along-strike evolution such large-scale detachment understood. It has been proposed that with increasing amounts extension, faulting favors formation isostatically induced, longitudinal transverse folds consequently basin inversion area maximum displacement (e.g. Kapp 2008; Osmundsen & Péron-Pinvidic, 2018). 4D configuration is then controlled by (potential) lateral linkage which may result complex geometries.</p><p>In this study, we use interpretation 3D- seismic reflection data from necking domain Mid-Norwegian rifted margin discuss effects study demonstrates how successive incision master induce a structural relief response folding. In inner parts south Vøring northeastern Møre basins, Klakk Main Fault Complexes form outer breakaway western boundary Frøya High. central High contains remnants metamorphic core complex, interpret as an parallel turtleback-structure. turtleback flanked two main synclinal depocenters constituting basin, whose location corresponds crustal taper break domain. We attribute exhumation Late Jurassic-Early Cretaceous along Complexes. Southwest High, links Turtleback previously interpreted Gossa near where Complex incises Slørebotn detachment. Subbasin forms keel rafted blocks, recognizable also north ‘Frøya Turtleback’ towards Halten Terrace. find pre-rift template heterogeneity facilitated differential after rifting, architecture was likely localized isostatic uplift, faults.</p>