D. C. Twichell M. C. Roberts S. Vanderburgh Steven W. Hostetler C. D. Peterson 2016 <p><span>The Columbia River Littoral Cell (CRLC), a high-wave-energy littoral system, extends 160&nbsp;km alongshore, generally north of the large Columbia River, and 10–15&nbsp;km in across-shelf distance from paleo-beach backshores to about 50&nbsp;m present water depths. Onshore drill holes (19 in number and 5–35&nbsp;m in subsurface depth) and offshore vibracores (33 in number and 1–5&nbsp;m in subsurface depth) constrain inner-shelf sand grain sizes (sample means 0.13–0.25&nbsp;mm) and heavy mineral source indicators (&gt;&nbsp;90% Holocene Columbia River sand) of the inner-shelf facies (≥&nbsp;90% fine sand). Stratigraphic correlation of the transgressive ravinement surface in onshore drill holes and in offshore seismic reflection profiles provide age constraints (0–12&nbsp;ka) on post-ravinement inner-shelf deposits, using paleo-sea level curves and radiocarbon dates. Post-ravinement deposit thickness (1–50&nbsp;m) and long-term sedimentation rates (0.4–4.4&nbsp;m&nbsp;ka</span>^−&nbsp;1<span>) are positively correlated to the cross-shelf gradients (0.36–0.63%) of the transgressive ravinement surface. The total post-ravinement fill volume of fine littoral sand (2.48&nbsp;×&nbsp;10</span>¹⁰<span>&nbsp;m</span>³<span>) in the inner-shelf represents about 2.07&nbsp;×&nbsp;10</span>⁶<span>&nbsp;m</span>³<span>&nbsp;year</span>^−&nbsp;1<span> fine sand accumulation rate during the last 12&nbsp;ka, or about one third of the estimated middle- to late-Holocene Columbia River bedload or sand discharge (5–6&nbsp;×&nbsp;10</span>⁶<span>&nbsp;m</span>³<span>&nbsp;year</span>^−&nbsp;1<span>) to the littoral zone. The fine sand accumulation in the inner-shelf represents post-ravinement accommodation space resulting from 1) geometry and depth of the transgressive ravinement surface, 2) post-ravinement sea-level rise, and 3) fine sand dispersal in the inner-shelf by combined high-wave-energy and geostrophic flow/down-welling drift currents during major winter storms.</span></p> application/pdf 10.1016/j.margeo.2016.05.007 en Elsevier Accommodation space in a high-wave-energy inner-shelf during the Holocene marine transgression: Correlation of onshore and offshore inner-shelf deposits (0–12 ka) in the Columbia River littoral cell system, Washington and Oregon, USA article