Sedimentology of a tidal point-bar within the fluvial–tidal transition

Alluvial architecture of mid‐channel fluvial–tidal barforms: The mesotidal Lower Columbia River, Oregon/Washington, USA

“…Moreton & Carter, 2015). Modern FTT barforms have thus received a lot of recent attention (Smith, , 1989Smith et al, 2009;Choi, 2010;Sisulak & Dashtgard, 2012;Choi et al, 2013;Johnson & Dashtgard, 2014;Carling et al, 2015;Prokocki et al, 2015;Leuven et al, 2016) in order to establish how fluvial-tidal processes alter their morphology and alluvial architecture. Most sedimentological observations from modern FTTs, however, are restricted to bed-scale trenches and cores (e.g.…”

“…Most sedimentological observations from modern FTTs, however, are restricted to bed-scale trenches and cores (e.g. Dalrymple & Rhodes, 1995;Choi et al, 2004;van den Berg et al, 2007;Baker et al, 2010;Martinius & Van den Berg, 2011;Sisulak & Dashtgard, 2012;Peterson et al, 2014;Carling et al, 2015;Prokocki et al, 2015;Ghinassi et al, 2018), whilst seismic data of bar-scale architecture is scarce, limited in its spatial resolution and confined to individual sandbanks, or -tidal transition as tidal-processes increase in magnitude and frequency in the downstreamdirection. This model assumes that the increased deposition of relatively thick silt/mud horizons within point-bar accretion-sets is primarily the product of suspension-fallout of fine-grained sediment during tidal slackwater periods, and enhanced flocculation and deposition of fines within the turbidity-maximum zone.…”

Three-dimensional meander bend flow within the tidally influenced fluvial zone

“…The current data suggest that the balance between the maximum fluvial and tidal flows, combined with the duration and strength of the secondary currents, appears to be significant to the geometry and migration of meander bends within this zone. It is possible that there is a local gravel deposit present at this location creating a stable core to the point bar (Carling et al, 2015), which could only be moved at the maximum flow velocities in both landward and seaward directions. It is possible that there is a local gravel deposit present at this location creating a stable core to the point bar (Carling et al, 2015), which could only be moved at the maximum flow velocities in both landward and seaward directions.…”

A novel approach for prediction of lithological heterogeneity in fluvial point‐bar deposits from analysis of meander morphology and scroll‐bar pattern

“…Pioneering studies of Jones et al (1993) and van den Berg et al (2007) linked variations in fluvial discharge with sandmud alternations in Inclined Heterolithic Stratification. Recent studies on the fluvial-tidal transition zone (see Ashworth et al, 2015 for a review) have focussed their attention on the role of tidal currents in modulating fluvial pointbar sedimentation (Dalrymple & Choi, 2007;Martinius & Gowland, 2011;Shiers et al, 2014;Carling et al, 2015;Gugliotta et al, 2016a, b) and have highlighted the different aspects of tidal signature on point-bar sedimentation. Choi et al (2004) R i c h a r d s e t a l .…”