Figure 23. Particle size distributions for surface and subsurface samples at Fitzhugh Bar (flood-plain kilometer 15.5), Chetco River, Oregon, Social Security Bar (flood-plain kilometer 6.1), and Tidewater Estuary Bar (flood-plain kilometer 3). At each bar, surface material was sampled at three locations along the bar axis: bar apex, midbar, and toe of bar using Wolman (1954) particle count procedure with measurement template. Subsurface material sampled volumetrically at bar apex and sieved by U.S. Geological Survey sediment laboratory in Vancouver, Washington. Bedload sample size distributions for December 28, 2008, and February 25, 2009, sampling trips shown for comparison with the surface and subsurface samples from the nearby Fitzhugh Bar. Bedload samples analyzed by U.S. Geological Survey sediment laboratory in Vancouver, Washington.

Revised July 2012

First posted May 26, 2010