Geochemistry of rocks, precipitation, and water sources from Pinnacles National Park, California, 2016-2017

Surface water, springs and wells in Pinnacles National Park (San Benito and Monterey Counties, CA) were sampled in the Fall of 2016 and Spring of 2017. Field parameters such as in situ pH, TDS/conductivity, and temperature were assessed. GPS coordinates for all samples were taken. Comprehensive groundwater chemistry, including major and minor elements, alkalinity, nutrients (and other parameters), Sr isotopes and REE concentrations, was analyzed at the National Water Quality Lab, USGS, Denver CO; and in USGS labs in Menlo Park, CA. One field visit on 8/20/2017 was made to obtain rock samples from the volcanic and sedimentary rocks in and around the park, which were digested and analyzed for whole rock chemistry (XRF, OES, ICP MS) by the Analytical Chemistry Lab (Mineral Resources Program, USGS, Denver CO). Sr isotopes for these samples were analyzed in the Menlo Park Metal Isotope Lab at the USGS. Precipitation was collected in a bulk collector during the winter of 2016-2017 and the chemistry and Sr isotopes of bulk samples was analyzed by ICP-MS or TIMS at the USGS Metal Isotope Lab in Menlo Park, CA.