Date of this Version
Analyses of more than 400 water samples collected from creeks and rivers draining into Yellowstone Lake, hydrothermal vents and water-column profiles within Yellowstone Lake, and subaerial hot springs and geysers throughout Yellowstone National Park (the Park) are reported. The samples were collected from 1996 to 2004. All of the water samples were collected and analyzed as part of the USGS Mineral Resources Program Project, Integrated Geoscience Studies of the Greater Yellowstone Area. Goals of this study are to provide state-of-the-art chemical determinations of more than 45 elements and species to help understand the influences of hydrothermal processes within Yellowstone National Park.
Hydrothermal vents within Yellowstone Lake were sampled during 1996–2004. Sampling of creeks contributing to Yellowstone Lake began in 1997 and continued through 1999. Four water-column profiles were collected within Yellowstone Lake in both 1997 and 1998. Water samples were collected from subaerial geysers and hot springs throughout Yellowstone National Park during 1998–2002.
In 1999, mixing experiments were conducted using water samples collected from four subaerial hot springs: three in Norris Geyser Basin and one at West Thumb Geyser Basin. These thermal-water samples were mixed with Yellowstone Lake water to simulate processes at sublacustrine vents and to evaluate conservative–nonconservative behavior of elements during mixing. The results of these experiments are discussed in Balistrieri and others (this volume), and the full data sets are presented here.
The data reported in this paper clearly show the influence of hydrothermal processes on waters within Yellowstone National Park. Yellowstone Lake hydrothermal- indicator elements (As, B, Cl, Cs, Cu, Ge, Hg, Li, Mo, Sb, and W) as defined by Balistrieri and others (this volume) delineate areas of hydrothermal influx. The differences in the levels of these elements between the creek data and water-column profiles indicate an influx of hydrothermal water within Yellowstone Lake. The water-column samples have higher values of the hydrothermal-indicator elements than the creeks flowing into the lake; therefore significant input of hydrothermal-indicator elements from the hydrothermal vents within the lake is indicated.
There are large variations in the values of the indicator elements among vents in Yellowstone Lake. The values of the hydrothermal-indicator elements are elevated for all of the vent samples, but a group of the West Thumb vents contain the highest values. This could indicate more active vents and (or) less mixing with lake water during sampling or during ascent to the lake floor. The subaerial features in the Park also show considerable variations in the values of the indicator elements. Some thermal features in the Park, such as Porkchop and Green Dragon Geysers in Norris Geyser Basin, have highly elevated hydrothermal- indicator-element values, while other features have values similar to Yellowstone Lake water, which is 99 percent meteoric water. These differences must reflect varying amounts of hydrothermal activity and input in these areas.