Evolution of shelf-margin clinoforms and deep-water fans during the middle Eocene in the SØrvestsnaget Basin, southwest Barents Sea

Seismic expression of depositional elements associated with a strongly progradational shelf margin: northern Santos Basin, southeastern Brazil

“…The increase on dip angles from older to youngest slope clinoforms (Fig. 7B) in association 1 suggests an increase in sediment supply and sediment caliper as a result of base level fall and erosion on the shelf (e.g., Zecchin & Catuneanu, 2013;Safronova et al, 2014). While in the first parts of association 1, lower-angle slope clinoforms (maximum slope angle of approximately 1º) are associated to flat to mildly descending shelf-edge trajectories, steeper clinoforms in the last stages of the association (maximum slope angle reaching 2º) are related to strongly descending trajectories (Figs.…”

“…However, considering the relatively high-sediment supply in relation to the mainly falling base-level trend, it seems coherent to ponder that the more distal submarine fans were fed by turbidity current during both rising and falling of relative sea level (e.g., Mutti & Normark, 1991;Burgess & Hovius, 1998;Shanmugam, 2002;Dixon et al, 2012;Safronova et al, 2014;de Gasperi & Catuneanu, 2014) (Fig. 14).…”

“…Although sand transport to the deep-sea is favored by forced regressions (e.g., Muto & Steel, 2002;Helland-Hansen & Hampson, 2009), occurrence and volume of turbidites are not exclusively controlled by base-level falls (e.g., Burgess & Hovius, 1998;Carvajal & Steel, 2006;Dixon et al, 2012;Safronova et al, 2014;Berton & Vesely, 2016). Turbidites were identified in all seismic facies associations formed during base-level falls, but they are more frequently observed on the bottomset of clinoforms from association 1, in which well-developed shelf-margin deltas/shoreface deposits occur (Figs.…”

“…Therefore, the primary control on turbidite deposition was the sediment supply (e.g., Burgess & Hovius, 1998;Dixon et al, 2012;Safronova et al, 2014), although the influence of falling to low relative sea level was crucial to the development of shelf-margin deltas/shoreface deposits that were the main feeders for deep-water sands (e.g., Mellere et al, 2002;Johannessen & Steel, 2005;Dixon et al, 2013). The architectural pattern of the turbidite systems (channels ending in frontal splays) is well known and well documented in the classic literature on deep-water systems (e.g., Mutti & Normark, 1991;Posamentier & Erskine, 1991;Shanmugam, 2000;Sylvester et al, 2012;de Gasperi & Catuneanu, 2014).…”

“…Slope-accretion clinoforms are composed of topset, foreset and bottomset domains. The topset corresponds to the continental to shelfal domain, extending to the shelf margin and encompassing reflectors that dip in very low angles towards the basin (Safronova et al, 2014). An inflexion marks the shelf break, when gradients become steeper in slope areas (foreset domain).…”