Deformation structures in organic-rich shales

Tectono‐stratigraphic development of a salt‐influenced rift margin: Halten Terrace, offshore Mid‐Norway

“…More coherent, moderate‐amplitude reflections are locally developed, with an reflection mean strength (RMS) amplitude extraction around one such event revealing several curvilinear, convex‐to‐the‐west, high‐amplitude lineations striking parallel to the BFC (Figure 14b). Similar features are imaged by Løseth et al (2011) in the overlying Lange Formation (Lower Cretaceous) and in well 6407/5‐1, where a section of deformed Late Jurassic Spekk Formation is encased in the younger, Early Cretaceous Lange Formation. We interpreted these arcuate features as the seismic expression of a 50 m thick Spekk Formation slide complex, sourced from the BFC and that translated westwards into the Gimsan Basin.…”

“…We interpreted these arcuate features as the seismic expression of a 50 m thick Spekk Formation slide complex, sourced from the BFC and that translated westwards into the Gimsan Basin. A RMS extraction taken from our dataset through the Lower Cretaceous slide complex described by Løseth et al (2011) reveals a series of curvilinear lineations similar to those we have mapped and imaged in the Spekk Formation. Thus, by analogy, we interpret the curvilinear seismic facies in the Spekk Formation to represent a submarine slide complex (Figure 14c).…”

“…(a) RMS amplitude extraction from intra‐Spekk reflection event showing high amplitude curvi‐linear anomalies expanding away from the Vingleia Fault Complex in the east. (b) RMS extraction from Early Cretaceous reflection event described by Løseth et al (2011) as a large slope failure complex comprised of Spekk Formation shale which exhibits a similar curvi‐linear pattern as seen in the intra‐Spekk event suggesting a slope failure origin for those features. (c) Seismic profile orientated N–S showing the deformation at intra‐Spekk Formation level and also in the Early Cretaceous section as described by Løseth et al (2011)…”

The Middle Jurassic to lowermost Cretaceous in the SW Barents Sea: Interplay between tectonics, coarse‐grained sediment supply and organic matter preservation

“…Wavy reflectors are interpreted as faulted beds, where the offset of the faults is below seismic resolution. Similar structures were described by Løseth, Wensaas, and Gading (2011b). Alternatively, these wavy reflectors can represent incisions (Figure 11e).…”

Revisiting the Hubbert–Rubey pore pressure model for overthrust faulting: Inferences from bedding-parallel detachment surfaces within Middle Devonian gas shale, the Appalachian Basin, USA

“…Maturation-related detachment is a relatively new idea that comes from Peter Cobbold's group at Rennes, France (Cobbold, 1999;Cobbold et al, 2004Cobbold et al, , 2013Loseth et al, 2011). There are examples in several basins of the globe including the Niger Delta (Cobbold et al, 2009), the North Sea (Loseth et al, 2011) and in the Andes where maturation fronts and deformation fronts seem to coincide (Cobbold, 2005;Cobbold and Castro, 1997). In particular, an association between beef and detachments in source rock in the Magellan Basin is consistent with the maturation-related detachment hypothesis .…”