The linkage between fault throw and footwall scarp erosion patterns: an example from the Bremstein Fault Complex, offshore Mid‐Norway

Abstract

Studies of normal fault systems in modern extensional regimes (e.g. Basin and Range), and in exhumed, ancient rift basins (e.g. Gulf of Suez Rift) have shown a link between the evolution of fault-related footwall topography and associated erosional drainage systems. In this study, we use 3D seismic reflection data to image the footwall crest of a gravity-driven fault system developed during late Middle Jurassic to Early Cretaceous rifting on the Halten Terrace, offshore Mid-Norway. This 22-km-long fault system lacks significant footwall uplift, with hangingwall subsidence accommodating throw accumulation on the fault system. Significant erosion has occurred along the length of the footwall crest and is defined by 96 catchments characterized by erosional channels. These erosional channels consist of small, linear systems up to 750 m long located along the front of the fault footwall. Larger, dendritic channel systems extend further back (up to 3 km normal to fault strike) into the footwall. These channels are up to 7 km long, up to 50 m deep and up to 1 km wide. Fault throw varies along strike, with greatest throw in the centre of the fault decreasing towards the fault tips; localized throw minima are interpreted to represent segment linkage points, which were breached as the fault grew. Comparison of the catchment location to the throw distribution shows that the largest catchments are in the centre of the fault and decrease in size to the fault tips. There is no link between the location of the breached segment linkage points and the location and size of the footwall catchments, suggesting that the first-order control on footwall erosion patterns is the overall faultthrow distribution.

Unravelling key controls on the rift climax to post‐rift fill of marine rift basins: insights from 3D seismic analysis of the Lower Cretaceous of the Hammerfest Basin, SW Barents Sea

“…Variability along the strike of the main bounding faults : In this study, we consider the variability in the throw and the steps in the main bounding faults to be a factor affecting the depositional systems and the input of sediments into the basin, as it has been considered previously (Gawthorpe et al ., ; Gupta et al ., ; McLeod et al ., ; Elliott et al ., , ). High accommodation space was generated in faults with higher throw, for example in the southern bounding fault (TFFC).…”

“…affecting the depositional systems and the input of sediments into the basin, as it has been considered previously (Gawthorpe et al, 1990;Gupta et al, 1998;McLeod et al, 2002;Elliott et al, 2012Elliott et al, , 2017. High accommodation space was generated in faults with higher throw, for example in the southern bounding fault (TFFC).…”

“…In summary, during the rift climax stage, the geometry, distribution of depositional systems and the input of sediments in a basin are controlled by the interaction of several variables such as: 1) variability along the strike of the main bounding faults (Gawthorpe et al, 1990;Gupta et al, 1998;McLeod et al, 2002;Elliott et al, 2012Elliott et al, , 2017Elliott et al, , 2017; 2) diachronous movement of the faults; and 3) nature of the feeder system (Reading & Richards, 1994;Stow et al, 1996;Galloway, 1998;Gawthorpe & Leeder, 2000;Leppard & Gawthorpe, 2006). Although variations in footwall lithology are not considered here, this may be an important factor affecting the amount of coarsegrained sediment transported into the basin (McArthur et al, 2013).…”

Insights into the development of major rift‐related unconformities from geologically constrained subsidence modelling: Halten Terrace, offshore mid Norway

“…3; Dalland et al, 1988;Richardson et al, 2005). 3; Dalland et al, 1988;Elliott et al, 2012). Not Formation) formations ( Fig.…”

“…The post-Triassic structural evolution of the northern part of the Halten Terrace has been strongly influenced by a thick sequence of Triassic evaporites, which have resulted in the formation of a range of complex, rift-and halokinesis-related structural styles (Pascoe et al, 1999;Corfield & Sharp, 2000;Marsh et al, 2010;Elliott et al, 2012). The Triassic evaporites are thin and largely immobile in the southern part of the Halten Terrace and thickskinned, basement-involved faulting dominates the structural style and results in the formation of a large, east-dipping half-graben (Figs 1b and 2).…”