Sr and U concentrations and radiogenic isotope compositions (87Sr/86Sr, 234U/238U) of thermal waters, streamflow, travertine, and rock samples along with U-Th disequilibrium ages for travertine deposits from various locations in Yellowstone National Park,

The radiogenic isotope ratios of strontium (Sr) and uranium (U), specifically 87Sr/86Sr and 234U/238U, are useful tracers of water-rock interactions.  Sr isotopic compositions in groundwater are mostly controlled by dissolution or exchange with Sr contained in aquifer rocks whereas the U isotopic compositions are more controlled by chemical 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 water samples from 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, 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 inherited from their source water at the time they formed.