Whole-Rock Geochemistry for Eocene Volcanic Rocks of the Toutle 7.5-Minute Quadrangle, Washington

This data release contains geochemical data for 52 rock samples collected by Russell C. Evarts and colleagues from 1992 to 1999 to support geologic mapping of the Toutle 7.5-minute quadrangle in southwest Washington. Fifty samples were analyzed in analytical laboratories of the U.S. Geological Survey (USGS) and three samples were analyzed at the Peter Hooper GeoAnalytical Laboratory at Washington State University in Pullman, Washington. Most major-element abundances were determined using X-ray fluorescence (XRF) and are expressed as oxides in weight percent. Minor-element abundances are expressed in parts per million and were mostly determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES) but some were determined using XRF and possibly by other methods. Major- and trace-element abundances are raw unnormalized values as reported by the source laboratory. Major element abundances are also expressed as oxides normalized volatile free to 100 weight percent with total iron as FeO. Unpublished field notes and a draft geologic map were used determine sample locations and, where possible, to assign map units equivalent to those of the adjacent Silver Lake 7.5-minute quadrangle of Evarts (2001, https://doi.org/10.3133/mf2371). Many of the samples in this data release are included in the USGS National Geochemical Database and in the compilation of du Bray and others (2006, https://doi.org/10.3133/ds155). This data release improves upon the locations presented in these previous compilations and is intended to guide geologic studies of igneous rocks within the Toutle 7.5-minute quadrangle.