Skip to main content

Organization

Laboratory & Analytical Services Division
thumbnail
Sediment cores were collected in the Cache Creek Settling Basin (CCSB), Yolo County, California, during October 2011 at 10 locations (borehole sites) and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Detailed subsampling (3-centimeter intervals) was done at total of seven locations: six along an east-west transect in the southern part of the Cache Creek Settling Basin and at one in the northern part of the basin for analyses of total mercury; organic content; and cesium-137, which was used for dating. This data release reports results of the analyses of each subsample of these...
thumbnail
Slug additions are often the most accurate method for determining discharge when traditional current meter or acoustic measurements are unreliable because of high turbulence, rocky streambed, shallow or sheet flow, or the stream is physically inaccessible (e.g., under ice or canyon walls) or unsafe to wade (Zellweger et al., 1989, Kilpatrick and Cobb 1984, Ferranti 2015). The slug addition method for determining discharge requires an injection of a known amount of a single salt and high-frequency downstream measurement of solute concentration to capture the response curve (Kilpatrick and Cobb 1984). A new slug method was developed to determine stream discharge utilizing specific conductance and ionic molal conductivities...
thumbnail
Biogeochemical processes are key drivers of chemical solubility and mobilization. Understanding these processes will lead to improved predictive capabilities and may aid with watershed management decisions. This data release presents results from the Boulder Creek, Colorado watershed, including analyses of water and sediment. From April to August 2019, water samples were collected weekly at 2 sites along Boulder Creek and 4 tributary sites draining into Boulder Creek. In August 2022, water samples were collected every 2 hours for 34 hours at 2 sites on Boulder Creek (upstream and downstream of the city of Boulder). Samples for both studies were analyzed for major cations and anions, dissolved organic carbon, UV...
thumbnail
Atmospheric deposition of reactive nitrogen (Nr) can impact the soil microbial community structure and function and thus ecosystem processing and export of nutrients. Ecosystem response to atmospheric inputs of nitrogen depends on several factors, including elevational climate conditions (freeze/thaw cycles, precipitation), geology, soil and vegetation type, N speciation and microbial community structure. The focus of this study was to evaluate how spatial and seasonal variations in N deposition affect the ability of soil microbial communities to process N along an elevational gradient (1700 to 3015 meters) from plains to subalpine ecosystems west of Boulder, Colorado. In conjunction with a study measuring the variability...
thumbnail
In support of paleoclimatology investigations, samples of mammillary calcite, calcitic folia, and flowstone were collected by the U.S. Geological Survey in Devils Hole and Devils Hole Cave 2, Nevada, between 1983 and 1996. These samples came from about 60 m below to 9 m above the modern water table in these caverns. To determine δ18O and δ13C time series spanning the interval 567.7–4.5 ka, more than a thousand samples were milled and analyzed for their δ18O and δ13C values. To determine time-series ages, more than a hundred samples were analyzed using uranium-series dating. Many of these measurement results have not been published. Herein, we provide previously unpublished δ13C and δ18O values, and we provide unpublished...
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.