Chemical changes in hot springs, as recorded by thermal waters and their mineral deposits, provide a window into the evolution of Yellowstone’s postglacial hydrothermal system. Travertine precipitated from thermal waters provide a record of chemical changes through time because they can be dated using U-series disequilibrium geochronology. These temporal data, along with measured radiogenic 87Sr/86Sr and stable isotope (carbon and oxygen) compositions and elemental concentrations, allow for the investigation of changes in hydrothermal system chemistry over time. This data release contains analyses conducted on samples of hydrothermal travertine collected from Upper and Lower Geyser Basins and near Madison Junction in Yellowstone National Park between April 2018 and July 2022. They include major and trace element concentrations, strontium (87Sr/86Sr), carbon (13C/12C), and oxygen (18O/16O) isotopic compositions, U-series disequilibrium ages (230Th-U), and X-ray diffraction data.

Chemical changes in hot springs, as recorded by thermal waters and their mineral deposits, provide a window into the evolution of Yellowstone’s postglacial hydrothermal system. Travertine precipitated from thermal waters provide a record of chemical changes through time because they can be dated using U-series disequilibrium geochronology. These temporal data, along with measured radiogenic 87Sr/86Sr and stable isotope (carbon and oxygen) compositions and elemental concentrations, allow for the investigation of changes in hydrothermal system chemistry over time. This data release contains analyses conducted on samples of hydrothermal travertine collected from Upper and Lower Geyser Basins and near Madison Junction in Yellowstone National Park between April 2018 and July 2022. They include major and trace element concentrations, strontium (87Sr/86Sr), carbon (13C/12C), and oxygen (18O/16O) isotopic compositions, U-series disequilibrium ages (230Th-U), and X-ray diffraction data.

Radiogenic isotopes of strontium and uranium (87Sr/86Sr and 234U/238U) are useful tracers of water-rock interactions. Sr isotopic signatures in groundwater are derived by dissolution or exchange with Sr contained in aquifer rock whereas U isotopic signatures are more controlled by physicochemical and kinetic processes during groundwater flow. Insights into groundwater circulation patterns through the shallow subsurface at Yellowstone National Park can be aided by investigations of these isotopes. This data release contains tables with new isotope data consisting of concentrations (Sr, U) and radiogenic-isotope compositions (87Sr/86Sr, 234U/238U) for samples of thermal springs and geysers focused largely on the Upper Geyser Basin, but from other geothermal areas as well. Sr isotopes were also analyzed in samples of streamflow from several different areas in the Park as well as in samples of whole rock or mineral separates as a means of better defining sources of Sr that are incorporated into thermal water. Finally, authigenic mineral deposits precipitated from spring discharge inherit the Sr- and U-isotopic composition of the water from which they formed. Travertine precipitated from several areas in the Upper Geyser Basin were analyzed as a means of assessing their ages, determined by U-Th disequilibrium methods, and the Sr- and U-isotopic compositions of their source water at the time they formed.

Radiogenic isotopes of strontium and uranium (87Sr/86Sr and 234U/238U) are useful tracers of water-rock interactions. Sr isotopic signatures in groundwater are derived by dissolution or exchange with Sr contained in aquifer rock whereas U isotopic signatures are more controlled by physicochemical and kinetic processes during groundwater flow. Insights into groundwater circulation patterns through the shallow subsurface at Yellowstone National Park can be aided by investigations of these isotopes. This data release contains tables with new isotope data consisting of concentrations (Sr, U) and radiogenic-isotope compositions (87Sr/86Sr, 234U/238U) for samples of thermal springs and geysers focused largely on the Upper Geyser Basin, but from other geothermal areas as well. Sr isotopes were also analyzed in samples of streamflow from several different areas in the Park as well as in samples of whole rock or mineral separates as a means of better defining sources of Sr that are incorporated into thermal water. Finally, authigenic mineral deposits precipitated from spring discharge inherit the Sr- and U-isotopic composition of the water from which they formed. Travertine precipitated from several areas in the Upper Geyser Basin were analyzed as a means of assessing their ages, determined by U-Th disequilibrium methods, and the Sr- and U-isotopic compositions of their source water at the time they formed.

Strontium isotope ratios of lavas from Hawaiʻi were analyzed by thermal ionization mass spectrometry (TIMS) at the Southwest Isotope Research Laboratories of the U.S. Geological Survey (USGS) in Denver. There were at total of 427 analyses of samples obtained from the field, the collections of the USGS Hawaiian Volcano Observatory (HVO), the University of Hawaiʻi, and the Smithsonian Institution. The samples originated from Kīlauea (historical and prehistoric summit and rift zone lavas), Mauna Loa (historical lavas), and Lōʻihi (submarine lavas of unknown age). Data for associated reference materials are described in the process steps. The Sr isotope ratios may be used to test models for the magmatic plumbing system of each volcano. This data release supersedes the following data release: Pietruszka, A.J., 2019, Strontium isotope ratios of lavas from Kīlauea Volcano, Hawaiʻi: U.S. Geological Survey data release, https://doi.org/10.5066/P9YMNIAT.

Strontium isotope ratios of lavas from Hawaiʻi were analyzed by thermal ionization mass spectrometry (TIMS) at the Southwest Isotope Research Laboratories of the U.S. Geological Survey (USGS) in Denver. There were at total of 427 analyses of samples obtained from the field, the collections of the USGS Hawaiian Volcano Observatory (HVO), the University of Hawaiʻi, and the Smithsonian Institution. The samples originated from Kīlauea (historical and prehistoric summit and rift zone lavas), Mauna Loa (historical lavas), and Lōʻihi (submarine lavas of unknown age). Data for associated reference materials are described in the process steps. The Sr isotope ratios may be used to test models for the magmatic plumbing system of each volcano. This data release supersedes the following data release: Pietruszka, A.J., 2019, Strontium isotope ratios of lavas from Kīlauea Volcano, Hawaiʻi: U.S. Geological Survey data release, https://doi.org/10.5066/P9YMNIAT.

Strontium isotope ratios of historical Kīlauea summit and rift lavas were analyzed by thermal ionization mass spectrometry (TIMS) at the Southwest Isotope Research Laboratories of the U.S. Geological Survey (USGS) in Denver. There were 151 analyses of 49 samples obtained from the field, the collections of the USGS Hawaiian Volcano Observatory (HVO), and the Smithsonian Institution. Data for associated reference materials are described in the process steps . The Sr isotope ratios may be used to test models for the volcano’s magmatic plumbing system.

This U.S. Geological Survey (USGS) data release contains strontium isotopic data from water and rock samples collected between 2000 and 2019 from the Mount Emmons area, central Colorado. The data include strontium isotopic compositions, 87Sr/86Sr, for surface- and groundwater samples collected from streams, springs, draining mines, piezometers, and drill holes and for leachates of rock samples collected from surface outcrops and drill core. Rock sample isotopic data are results from two-step leaching of samples from various lithologies within the study area. Drill core rock and water samples were collected from holes drilled in 2017 and 2018 as part of a U.S. Geological Survey and Department of Energy investigation of groundwater flowpaths in the Redwell basin. Complete water chemistry for samples analyzed in this study are presented in Johnson and others (2019). Whole-rock geochemical data for rock samples used in this study are published in Charnock and others (2022). Previously published strontium isotopic data from within the study area can be found in Manning and others (2008). Data are reported in a comma-separated values (CSV) file that lists the samples that were analyzed, drill hole identification number and depth (if applicable), latitude/longitude location information, and brief sample descriptions. All column headings and abbreviations are explained in the accompanying metadata.