Geochemical, mineralogical, and grain-size data for deep cores from the Cache Creek Settling Basin and streambed sediments from the Sacramento River watershed

The Cache Creek Settling Basin (CCSB) is a 13.3 km2 levee-bounded sediment retention basin located at the modern terminus of Cache Creek near the eastern boundary of Yolo County, approximately two miles NE of Woodland, California. The Cache Creek Settling Basin was constructed in 1937 by the U.S. Army Corps of Engineers to trap suspended sediment from the upper Cache Creek watershed during high-flow events, with the purpose of preserving the floodway capacity of the Yolo Bypass, a larger leveed floodway located downstream. This dataset includes subsamples from sediment cores and shallow streambank sediment collected from the Sacramento River watershed. Sediment cores were collected in the Cache Creek Settling Basin during October 2011 at two borehole sites and during August 2012 at four other borehole sites. Total core depths ranged from approximately 8.6 to 9.0 meters (28 – 30 feet). For three of the core sites, detailed subsamples were collected in 3-centimeter intervals at targeted depths. For all the core sites, detailed subsamples were collected in 20-centimeter intervals at targeted depths. Streambank samples were collected from 3 locations on the Sacramento River during August 2017 and from 3 locations on the Feather River and Cache Creek during November 2017. Each streambank sample is a composite of several surface samples composing the top 0-10 centimeters of surface material. Sediment core and streambank samples were analyzed for grain-size distribution, X-ray diffraction (XRD) for quantitative mineralogy, inductively coupled plasma – mass spectrometry (ICP-MS) for trace elements, and inductively coupled plasma – optical emission spectroscopy (ICP-OES) for major elements. This data release reports results of the analysis for each streambank sample and sediment core subsample, including quality-assurance data.