The major, minor, and trace element geochemistry of mineral scales from The Geysers geothermal field, California, USA

This data release provides quantitative whole rock geochemical results from The Geysers vapor-dominated geothermal field in California. The concentrations of major elements are reported in oxide weight percent by wavelength dispersive x-ray fluorescence (WDXRF), the concentrations for sixty elements are reported in elemental weight percent (pct) or parts per million (ppm) from inductively coupled plasma-optical emission spectrometry-mass spectrometry ICP-OES-MS analysis, mercury is reported in ppm by cold vapor atomic absorption spectrometry (CVAAS), and ammonium in ppm from automated colorimetry analysis. The analyses show significant enrichment of volatile elements and elements such as sulfur, boron, arsenic, and mercury. Mineral scales from the Northwest Geysers are characterized by high concentrations of ammonium and mercury while the mineral scales from the Central and Southeast Geysers are enriched in boron, iron and sulfur. The mineral scales from orifice plates and condensers contain significant concentrations of Cr, Ni, Co, Zn, and W which are common contaminants from rusted steel equipment.