This dataset is a compilation of samples collected from draining mine adits, including water and mineral precipitates, from several mines in California and Colorado. The Golinsky, Copper Bluff, and Afterthought Mines (located in northern California) and the Gold King mine (located in southern Colorado) have historically operated to recover metals including copper, lead, zinc, gold, silver and other resources (Albers and Robertson, 1961; USGS, 2005; USEPA, 2015). Data reported include field parameters, water chemistry, solid phase mineralogy and solid phase chemistry. Water samples collected from the four mine sites in 2019 were analyzed for unfiltered and filtered (0.1-0.45 micrometer) major and trace elements and iron oxidation state. At the Gold King Mine, water samples were collected at a draining adit and along a pipeline conveying water to a treatment plant. A small number of additional samples were collected from mine features near the Gold King Mine, including the Red and Bonita and Mogul Mines, as well as the American Tunnel. When available, solid samples were concurrently collected with the water samples and analyzed for bulk mineralogy and chemical composition. References: Albers, J.P., and Robertson, J.F., 1961, Geology and Ore Deposits of East Shasta Copper-Zinc District Shasta County, California: U.S. Geological Survey Professional Paper 338. [Also available at https://doi.org/10.3133/pp338.] U.S. Environmental Protection Agency, 2015, Gold King Mine - Watershed Fact Sheet: U.S. Environmental Protection Agency Fact Sheet 2015-08, accessed December 14, 2022, at https://www.epa.gov/sites/default/files/2015-08/documents/goldkingminewatershedfactsheetbackground.pdf. U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.

This U.S. Geological Survey (USGS) data release contains stream water chemistry and streamflow data collected in late August and early September, 2021 from 28 sites located throughout Colorado, USA. The sampled streams all drain high-elevation mountain watersheds in areas where the bedrock is hydrothermally altered and contains abundant sulfide minerals. Most sampled streams are therefore affected by natural acid-rock drainage. All sites had been sampled in prior years so that the 2021 data could be used to evaluate potential changes in stream water chemistry in recent decades. Streamflow was also quantified at most sites using data from a sodium chloride slug addition wherein specific conductivity readings were used as a surrogate for the tracer concentration.

This U.S. Geological Survey (USGS) data release contains stream water chemistry and streamflow data collected in late August and early September, 2021 from 28 sites located throughout Colorado, USA. The sampled streams all drain high-elevation mountain watersheds in areas where the bedrock is hydrothermally altered and contains abundant sulfide minerals. Most sampled streams are therefore affected by natural acid-rock drainage. All sites had been sampled in prior years so that the 2021 data could be used to evaluate potential changes in stream water chemistry in recent decades. Streamflow was also quantified at most sites using data from a sodium chloride slug addition wherein specific conductivity readings were used as a surrogate for the tracer concentration.

This U.S. Geological Survey (USGS) data release contains data from stream water, groundwater, and soil samples collected in 2019 and 2020 in the North Quartz Creek watershed in central Colorado. Fourteen streambank wells were installed in pairs at seven locations in August 2020 to capture the emerging groundwater from the left bank and right banks (relative to downstream-facing direction) and a synoptic sampling campaign was conducted to quantify metal contributions to the stream. A continuous, instream injection of sodium bromide (NaBr) was initiated at the head of the 5 km study reach several days prior to the synoptic sampling campaign and maintained throughout the duration of the study. Bromide concentrations were subsequently used to determine streamflow in the primary study reach (upper 1.3 km) using the tracer-dilution method, and as an indicator of hydrologic connections between North Quartz Creek and subsurface water. Streamflow was quantified in a secondary study reach (lower 3.7 km) using data from a series of sodium chloride slug additions wherein specific conductivity readings were used as a surrogate for the tracer concentration. Surface water samples were collected along North Quartz Creek including inflows from the left (LBI) and right (RBI) banks. Soil and sediment samples were collected along the transport path from source material (natural weathering and mine tailings/mine drainage) to the stream.

This U.S. Geological Survey (USGS) data release contains data from stream water, groundwater, and soil samples collected in 2019 and 2020 in the North Quartz Creek watershed in central Colorado. Fourteen streambank wells were installed in pairs at seven locations in August 2020 to capture the emerging groundwater from the left bank and right banks (relative to downstream-facing direction) and a synoptic sampling campaign was conducted to quantify metal contributions to the stream. A continuous, instream injection of sodium bromide (NaBr) was initiated at the head of the 5 km study reach several days prior to the synoptic sampling campaign and maintained throughout the duration of the study. Bromide concentrations were subsequently used to determine streamflow in the primary study reach (upper 1.3 km) using the tracer-dilution method, and as an indicator of hydrologic connections between North Quartz Creek and subsurface water. Streamflow was quantified in a secondary study reach (lower 3.7 km) using data from a series of sodium chloride slug additions wherein specific conductivity readings were used as a surrogate for the tracer concentration. Surface water samples were collected along North Quartz Creek including inflows from the left (LBI) and right (RBI) banks. Soil and sediment samples were collected along the transport path from source material (natural weathering and mine tailings/mine drainage) to the stream.

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.

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.

This data release is part of a study examining the use of near-stream groundwater discharge as a tool for Geochemical Exploration. Handcart Gulch is an unmined alpine watershed in Montezuma Mining District in the Colorado Front Range. The streambed is cemented by deep ferricrete deposits. Stream water, groundwater, and ferricrete samples were collected and analyzed to constrain the location of a possible concealed mineral occurrence identified by previous stream water sampling. Nineteen, near stream mini-boreholes were drilled through ferricrete using a portable, handheld, gasoline powered, rock coring drill manufactured by Shaw Tool. Boreholes were drilled within 2 meters of the stream on the east and west banks to constrain local-scale groundwater variations on either side of the stream. Ferricrete samples were logged and collected during drilling. A subset of ferricrete samples were analyzed for bulk chemistry and a deionized water leach quantified the water-soluble fraction from the ferricrete samples. Groundwater levels and field parameters (temperature, pH, specific conductance, and dissolved oxygen) were measured and groundwater samples were collected using a peristaltic pump for major and trace element chemistry. Environmental tracer samples (stable water isotopes, dissolved noble gases, helium isotopes, and tritium) were collected using a submersible double-valve pump manufactured by Solinst Canada Ltd. Stream water samples were collected adjacent to mini-boreholes over a period of two days with no major precipitation events.

This data release is part of a study examining the use of near-stream groundwater discharge as a tool for Geochemical Exploration. Handcart Gulch is an unmined alpine watershed in Montezuma Mining District in the Colorado Front Range. The streambed is cemented by deep ferricrete deposits. Stream water, groundwater, and ferricrete samples were collected and analyzed to constrain the location of a possible concealed mineral occurrence identified by previous stream water sampling. Nineteen, near stream mini-boreholes were drilled through ferricrete using a portable, handheld, gasoline powered, rock coring drill manufactured by Shaw Tool. Boreholes were drilled within 2 meters of the stream on the east and west banks to constrain local-scale groundwater variations on either side of the stream. Ferricrete samples were logged and collected during drilling. A subset of ferricrete samples were analyzed for bulk chemistry and a deionized water leach quantified the water-soluble fraction from the ferricrete samples. Groundwater levels and field parameters (temperature, pH, specific conductance, and dissolved oxygen) were measured and groundwater samples were collected using a peristaltic pump for major and trace element chemistry. Environmental tracer samples (stable water isotopes, dissolved noble gases, helium isotopes, and tritium) were collected using a submersible double-valve pump manufactured by Solinst Canada Ltd. Stream water samples were collected adjacent to mini-boreholes over a period of two days with no major precipitation events.