Field portable X-ray fluorescence and associated quality control data for the western Mojave Desert, San Bernardino County, California

These data on the concentrations of 27 selected elements were collected using a field portable (handheld) X-ray fluorescence (pXRF) instrument (Groover and Izbicki, 2016) equipped with a 4-watt Ta/Au X-ray tube on samples of 1) surficial alluvium, 2) rock, and 3) archived core material and drill cuttings from monitoring wells across an approximately 14,300 square kilometer area in the western part of the Mojave Desert, between 60 to 210 kilometers (km) northeast of Los Angeles, California. These samples were measured using a pXRF as part of a regional-scale investigation of naturally-occurring trace elements (including arsenic, chromium, and uranium) dissolved in groundwater (Groover and Izbicki, 2018), and a local-scale investigation of naturally-occurring and anthropogenic chromium dissolved in groundwater (Izbicki and Groover, 2016; Izbicki and Groover, 2018). These data also include pXRF quality assurance measurements done on three standard reference materials and a silicon dioxide blank.

These data contain more than 3,200 pXRF measurements and associated descriptive information on 335 samples of alluvium, rock, and archived core material and drill cuttings from 93 monitoring wells. An additional 564 pXRF measurements are on the three standard reference materials and silicon dioxide blank. Measurements were done between March 2015 and May 2018. These data are related to the following publications: Groover, K.D., and Izbicki, J.A., 2016, Elemental analysis using a handheld X-ray fluorescence spectrometer: U.S. Geological Survey Fact Sheet 2016-3043, 2p., https://doi.org/10.3133/fs20163043 Groover, K.D., and Izbicki, J.A., 2018, Selected trace-elements in alluvium and rocks, western Mojave Desert, southern California: Journal of Geochemical Exploration, https://doi.org/10.1016/j.gexplo.2018.09.005. Izbicki, J.A., and Groover, K., 2016, A plan for study of hexavalent chromium, Cr(VI) in groundwater near a mapped plume, Hinkley, California, 2016: U.S. Geological Survey Open-File Report 2016-1004, 12 p., https://doi.org/10.3133/ofr20161004 Izbicki, J.A., and Groover, K., 2018, Natural and man-made hexavalent chromium, Cr(VI), in groundwater near a mapped plume, Hinkley, California--study progress as of May 2017, and a summative-scale approach to estimate background Cr(VI) concentrations: U.S. Geological Survey Open-File Report, 28 p., https://doi.org/10.3133/ofr20181045