Mineralogy and grain size of surficial sediment from the Little Lost River and Birch Creek drainages, Idaho National Engineering Laboratory, Idaho

The U.S. Geological Survey 's Idaho National Engineering Laboratory project office, in cooperation with the U.S. Department of Energy, collected 13 samples of surficial sediments from the Little Lost River and Birch Creek drainages during August 1988 for analysis of grain-size distribution, bulk mineralogy, and clay mineralogy. Samples were collected from five sites in the channel of the Little Lost River, two sites from overbank deposits of the Little Lost River, five sites in the channel of Birch Creek, and one site from an overbank deposit of Birch Creek. Six samples from the Birch Creek channel and overbank deposits had a mean of 7.9 and median of 2.5 weight percent in the less than 0.062 mm fraction. The seven samples from the Little Lost River channel and overbank deposits had a mean of 34.5 and median of 23.8 weight percent for the same size fraction. Mineralogy data indicated that Birch Creek had larger mean percentages of quartz and calcite, and smaller mean percentages of total feldspar and dolomite than the Little Lost River deposits. Illite was the dominant clay mineral present in both drainages, but the Little Lost River deposits contained more smectite, mixed-layer clays, and kaolinite than the Birth Creek deposits. (USGS)