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

Ephemeral springs and other groundwater sources in Pinnacles National Park (San Benito and Monterey Counties, CA) were sample in the Spring and Fall of 2015-2017 during several field visits. Field parameters such as in-situ pH, TDS/conductivity, and temperature were assessed. GPS coordinates for all samples were taken. Comprehensive water 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 at the USGS in Menlo Park, CA. Tritium was analyzed by the Menlo Park Tritium Lab. One field visit in summer 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) and Sr isotopes and minor element and REE geochemistry in Menlo Park labs.