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USGS2007

Determination of total mercury in fillets of sport fishes collected from Folsom Reservoir, California, 2006

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom Reservoir in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fillets ranged from 0.031 to 0.20 micrograms per gram wet weight in rainbow trout (Oncorhynchus mykiss) samples and 0.071 to 0.16 micrograms per gram wet weight in bluegill (Lepomis macrochirus) samples. Mercury concentration was 0.98 microgram per gram wet weight in a single spotted bass (Micropterus punctulatus) sample, which was the only one in the sample set which exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Open-File Report↗

USGS2008

Chemical data for precipitate samples

During studies of sulfide oxidation in coastal areas of Prince William Sound in 2005, precipitate samples were collected from onshore and intertidal locations near the Ellamar, Threeman, and Beatson mine sites (chapter A, fig. 1; table 7). The precipitates include jarosite and amorphous Fe oxyhydroxide from Ellamar, amorphous Fe oxyhydroxide from Threeman, and amorphous Fe oxyhydroxide, ferrihydrite, and schwertmannite from Beatson. Precipitates occurring in the form of loose, flocculant coatings were harvested using a syringe and concentrated in the field by repetitive decanting. Thicker accumulations were either scraped gently from rocks using a stainless steel spatula or were scooped directly into receptacles (polyethylene jars or plastic heavy-duty zippered bags). Most precipitate samples contain small amounts of sedimentary detritus. With three jarosite-bearing samples from Ellamar, an attempt was made to separate the precipitate from the heavy-mineral fraction of the sediment. In this procedure, the sample was stirred in a graduated cylinder containing deionized water. The jarosite-rich suspension was decanted onto analytical filter paper and air dried before analysis. Eleven precipitate samples from the three mine sites were analyzed in laboratories of the U.S. Geological Survey (USGS) in Denver, Colorado (table 8). Major and trace elements were determined by inductively coupled plasma-mass spectrometry following multiacid (HCl-HNO3-HClO4-HF) digestion (Briggs and Meier, 2002), except for mercury, which was analyzed by cold-vapor atomic absorption spectroscopy (Brown and others, 2002a). X-ray diffraction (XRD) analyses were performed on powdered samples (<200 mesh) by S. Sutley of the USGS. Additional details regarding sample preparation and detection limits are found in Taggert (2002). Discussions of the precipitate chemistry and associated microbial communities are presented in Koski and others (2008) and Foster and others (2008), respectively.

Alaska↗

USGS2013

Sediment geochemistry of Corte Madera Marsh, San Francisco Bay, California: have local inputs changed, 1830-2010?

Large perturbations since the mid-1800s to the supply and source of sediment entering San Francisco Bay have disturbed natural processes for more than 150 years. Only recently have sediment inputs through the Sacramento-San Joaquin Delta (the Delta) decreased to what might be considered pre-disturbance levels. Declining sediment inputs to San Francisco Bay raise concern about continued tidal marsh accretion, particularly if sea level rise accelerates in the future. The aim of this study is to explore whether the relative amount of local-watershed sediment accumulating in a tidal marsh has changed as sediment supply from the Sacramento-San Joaquin Rivers has decreased. To address this question, sediment geochemical indicators, or signatures, in the fine fraction (silt and clay) of Sacramento River, San Joaquin River, San Francisco Bay, and Corte Madera Creek sediment were identified and applied in sediment recovered from Corte Madera Marsh, one of the few remaining natural marshes in San Francisco Bay. Total major, minor, trace, and rare earth element (REE) contents of fine sediment were determined by inductively coupled plasma mass and atomic emission spectroscopy. Fine sediment from potential source areas had the following geochemical signatures: Sacramento River sediment downstream of the confluence of the American River was characterized by enrichments in chromium, zirconium, and heavy REE; San Joaquin River sediment at Vernalis and Lathrop was characterized by enrichments in thorium and total REE content; Corte Madera Creek sediment had elevated nickel contents; and the composition of San Francisco Bay mud proximal to Corte Madera Marsh was intermediate between these sources. Most sediment geochemical signatures were relatively invariant for more than 150 years, suggesting that the composition of fine sediment in Corte Madera Marsh is not very sensitive to changes in the magnitude, timing, or source of sediment entering San Francisco Bay through the Delta. Nor does there appear to be a ubiquitous increase in the proportion of fine sediment from Corte Madera watershed accumulating in the marsh during the last 20 years when sediment inflows through the Delta have decreased to pre-disturbance levels. We conclude that a large, well-mixed reservoir, such as the transportable fine sediment pool in San Francisco Bay, is the primary source of sediment to Corte Madera Marsh, and this source buffers the marsh against changes in sediment supply from the Delta and local watersheds. This study also found that Corte Madera Marsh sediment between about 10-30 centimeters depth is highly contaminated with lead, likely a legacy of lead smelter operations near Carquinez Strait and leaded gasoline use.

California↗

USGS2015

Database creation, data quality assessment, and geochemical maps (phase V, deliverable 59)—Final report on compilation and validation of geochemical data

Under the World Bank-funded Second Projet de Renforcement Institutionnel du Secteur Minier de la Republique Islamique de Mauritanie (PRISM-II), this Phase V geochemistry report follows earlier Phase I and Phase II summary reports on geochemical data (U.S. Geological Survey, 2007 and Eppinger, 2007; respectively). All the reports are based on evaluations of geochemical data collected in 1999-2004 under an earlier World Bank program (PRISM-I) by the British Geological Survey (BGS) and the Bureau de Recherches Géologiques et Minières (BRGM) for the Government of Mauritania. There are no associated Phase III or IV reports. The geochemical sample media collected by the BGS and BRGM under the PRISM-I contract included rock, sediment, regolith, and soil samples. Details on sample collection procedures are in unpublished reports available from PRISM. These samples were analyzed under PRISM-I contract by ALS Chemex Laboratories using various combinations of modern methods including fire-assay inductively coupled plasma-atomic emission spectrometry (ICPAES) and ICP-mass spectrometry (ICP-MS) for Au; multi-acid digestion, atomic absorption spectroscopy (AAS) for Ag and As; 47-element, four-acid digestion, ICP-MS; 27-element, fouracid digestion, ICP-AES; special four-acid ICP-MS techniques for Pt and B; fire assay followed by ICP-AES for platinum-group elements; whole-rock analyses by wavelength dispersive X-ray fluorescence (XRF); special techniques for loss-on-ignition, inorganic C, and total S; and special ore-grade AAS techniques for Ag, Au, Cu, Ni, Pb, and Zn. Around 30,000 samples were analyzed by at least one technique. However, it is stressed here that: (1) there was no common sample medium collected at all sites, likely due to the vast geological and geomorphologic differences across the country, (2) the sample site distribution is very irregular, likely due in part to access constraints and sand dune cover, and (3) there was no common across-the-board trace element analytical package used for all samples. These three aspects fundamentally affect the ability to produce country-wide geochemical maps of Mauritania. Gold (Au), silver (Ag), and arsenic (As) were the three elements that were most commonly analyzed.

Open-File Report↗

USGS2020

Evaluation of the analytical methods used to determine the elemental concentrations found in the stream geochemical dataset compiled for Alaska

A recent U.S. Geological Survey data compilation of stream-sediment geochemistry for Alaska contains decades of analyses collected under numerous Federal and State programs. The compiled data were determined by various analytical methods. Some samples were reanalyzed by a different analytical method than the original, resulting in some elements having concentrations reported by multiple analytical methods. Consideration of the analytical methods used to determine the elemental concentrations is an important step in a mineral prospectivity analysis. We used the compiled data to compare concentrations of barium (Ba), cobalt (Co), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), and zinc (Zn) determined by different analytical methods to show how simple data comparisons can identify bias and provide a general sense of the comparability of different analytical methods. The elements were selected because they have a range of geochemical properties that may affect the performance of different analytical procedures. Generally, agreement between Ba, Co, Cu, Cr, Ni, Pb, and Zn concentrations is good for most quantitative methods that use a total decomposition of the sample. However, Cr concentrations typically were lower for methods using quantitative-instrumental analysis following a multi-acid dissolution technique that included hydrofluoric acid compared to those using sinter decomposition. Additionally, low- to middle-range concentrations for Co, Cr, Cu, Ni, Pb, and Zn by instrumental neutron activation (NA) and energy-dispersive x-ray spectroscopy (EDX) analyzed by the National Uranium Resource Evaluation (NURE) program have high uncertainty. Concentrations determined by methods that use partial decomposition of the sample generally correspond well to concentrations determined by methods that use a total decomposition technique, except for Ba and Cr. For Ba and Cr, partial decomposition techniques yield lower concentrations than those determined by methods that use a total decomposition technique. Comparison of Ba, Co, Cr, Cu, Ni, Pb, and Zn concentrations determined by semiquantitative visual six-step direct-current arc emission spectrography (ES_SQ) to those determined by quantitative methods using either a total or partial decomposition technique consistently show scatter that exceeds the values expected based on the range represented by the semiquantitative concentration. The data compilation includes a best-value determination that was selected based on the analytical method from the all concentration data for that sample. Ba, Cr, Co, and Zn concentrations determined by NA usually are selected as the best-value determination. However, the NURE-NA method was designed for high throughput and the uncertainty associated with low- and mid-range concentrations is greater than that of the multi-acid method used to reanalyze many samples. Selection of the multi-acid method over the NURE-NA method for Ba, Co, and Zn could be warranted. Additionally, concentrations determined by ES_SQ usually are selected as the best-value determination over all methods that use a partial decomposition of the sample. Substitution of concentrations determined by methods that use a partial decomposition for those of ES_SQ may be warranted for Co, Cu, Ni, Pb, and Zn. Regardless of the selection of the best-value determination, the dataset remains a mixed method dataset and the uncertainty due to differences in analytical methodology must be considered when using the dataset.

Alaska↗

USGS1980

Annotated bibliography of spectrophotometric studies in the system U-Fe-Se-S-O-H, 1967-78

Preparation of this bibliography was originally begun to supply background information on previous ultraviolet and visible spectrophotometric studies on various chemical species thought to be important in the formation of sedimentary uranium deposits; we also thought that preparing the bibliography would help direct experimental efforts to determine the association of iron and uranium with several metastable sulfur species. In compiling these references, however, we found that much work had been done on the chemical species of interest by using types of spectroscopy other than ultraviolet and visible spectrophotometry. The dimensions of the bibliography were therefore broadened to include a wide variety of spectral-measuring techniques to make this report useful to a larger audience.

Open-File Report↗

USGS1990

Reconnaissance wadi-sediment geochemical survey of the Bi'r Jarbuah area, Kingdom of Saudi Arabia

A reconnaissance wadi-sediment geochemical survey for gold was conducted in the Bi'r Jarbuah Area (lat 20° 45' 00"-21 ° 00' 00" N., long 43° 30' 00"- 43° 41' 00" K). The area is located in the northern part of a regional concentration of gold occurrences, the Jabal Ishmas-Wadi Tathlith gold belt. Panned concentrates and minus-80-mesh fractions were obtained from 300 samples collected from a 320 km 2 area and analysed by atomic-absorption spectroscopy. Analyses of the pannedconcentrate samples proved to be more definitive than sieved samples in delineating areas of mineralization. Most of the anomalous gold-and arsenic-bearing wadi-sediment samples are located along an irregular contact between gneissic and dioritic rocks in the center of an area characterized by the presence of subparallel dacitic dike swarms. Most of the ancient gold mines are also located along this contact. Gold is associated with arsenic but not with silver. Five areas containing gold-anomalies areas and 6 areas containing tellurium anomalies and the contact zone between the diorite and the paragneiss are recommended for further investigation of precious-metals resources.

Open-File Report↗

USGS1993

SPECtrum Processing Routines User's Manual Version 3 (program SPECPR)

Introduction The SPECtrum Processing Routines (SPECPR) is a large-scale interactive program for general one-dimensional array processing and optimized for reflectance spectroscopy data and analysis. The program processes one-dimensional arrays up to 4852 data points and the operations include addition, subtraction, multiplication, division, trigonometric functions, logarithmic and exponential functions, and many more specialized routines. The Specpr user interface is a menu driven, character command system with all user input entered as ascii characters to the program. User commands are thoroughly checked for the context in which they will be used. This provides for essentially all user input mistakes to be caught and appropriate error messages to be issued. The user interface also allows for command aliasing, variable substitutions, command history and batch command processing to occur at any point in the program. The user can also control his or her own variables, increment and decrement them, and monitor certain internal variables. This flexibility allows for sophisticated programming, e.g. from specific computations, to management of a database. All arrays are treated as one dimensional lists of numbers, each with an appropriate header for identification and history. Any array can be plotted versus another array, and each axis labeled appropriately. For example, you may plot a reflectance spectrum versus wavelength or wavelength versus reflectance. The array type is simply a label, so data like temperature versus time can be treated just as easily as a reflectance spectrum. Some routines are specific to certain purposes, however. For example, the Planck black body generator is specific to intensity versus wavelength, whereas a smoothing routine could operate equally on reflectance versus wavelength or temperature versus time. Each array element can have an error bar associated with it and errors are propagated through all appropriate routines. Data points can be marked deleted and deleted points are tracked appropriately. These features allow the program to be effectively used on real world data. This philosophy has resulted in a flexible system for which a user can manipulate data arrays efficiently. The program was designed for analysis of laboratory, field, telescopic, and spacecraft spectroscopic data, and although general in nature, there are biases built in. For example, horizontal axis labels default to wavelength in micrometers, but the defaults can be changed. Because of the orientation in Specpr to process planetary and terrestrial data, and the need to access such data, Specpr has been extended to have access to non-Specpr default file types. In particular, Specpr can "skewer" an 3-dimensional (3D) data file along any of the three axes. Further, block skewers can be done with the standard deviation of the mean computed for each channel in the block. Currently, Specpr can access any of the standard file types common in the terrestrial and planetary remote sensing communities. Details on 3D file I/O are given in Chapter 6. Specpr has multiple record types available within a single Specpr data file. Currently defined record types are data and text. In a data record, a standard one-dimensional array is held, along with its header information. The header information includes a title, history, dates and time of data acquisition and when the data were last processed, the user who processed the data, information typical of a spectrum like temperature and viewing geometry, as well as pointers to wavelengths, resolution, and text. If a spectrum is more than 256 channels in length, then the data gets put in succeeding records in the file, and the following records are continuation records. The second record type is the text, where a title and a block of text (up to 19 kbytes) can be stored. This record type is typically used for a description of samples, experiments, instruments, or data processing for a particular data set. It could also store the actual commands used to create a spectrum. The commands for a complicated plot for a publication might be stored in a text record. That way, you can easily regenerate the plot, or even write the commands to a non-Specpr file, modify them with any editor and re-execute them. The file types, text and command processing, combined with the math and special functions, provide for very powerful and general analysis tool. These facilities also provide the framework for database management.

Open-File Report↗

USGS1998

Analytical results for forty-two fluvial tailings cores and seven stream sediment samples from High Ore Creek, northern Jefferson County, Montana

Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana have been implicated in their detrimental effects on water quality with regard to acid-generation and toxic-metal solubility. Sediments, fluvial tailings and water from High Ore Creek have been identified as significant contributors to water quality degradation of the Boulder River below Basin, Montana. A study of 42 fluvial tailings cores and 7 stream sediments from High Ore Creek was undertaken to determine the concentrations of environmentally sensitive elements (i.e. Ag, As, Cd, Cu, Pb, Zn) present in these materials, and the mineral phases containing those elements. Two sites of fluvial deposition of mine-waste contaminated sediment on upper High Ore Creek were sampled using a one-inch soil probe. Forty-two core samples were taken producing 247 subsamples. The samples were analyzed by ICP-AES (inductively coupled-plasma atomic emission spectroscopy) using a total mixed-acid digestion. Results of the core analyses show that the elements described above are present at very high concentrations (to 22,000 ppm As, to 460 ppm Ag, to 900 ppm Cd, 4,300 ppm Cu, 46,000ppm Pb, and 50,000 ppm Zn). Seven stream-sediment samples were also analyzed by ICP-AES for total element content and for leachable element content. Results show that the sediment of High Ore Creek has elevated levels of ore-related metals throughout its length, down to the confluence with the Boulder River, and that the metals are, to a significant degree, contained in the leachable phase, namely the hydrous amorphous iron- and manganese-hydroxide coatings on detrital sediment particles.

Montana↗

USGS1999

Analytical results for 35 mine-waste tailings cores and six bed sediment samples, and an estimate of the volume of contaminated materials at Buckeye meadow on upper Basin Creek, northern Jefferson County, Montana

Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana have been implicated in their detrimental effects on water quality with regard to acid-generation and toxic-metal solubilization. Flotation-mill tailings in the meadow below the Buckeye mine, hereafter referred to as the Buckeye mill-tailings site, have been identified as significant contributors to water quality degradation of Basin Creek, Montana. Basin Creek is one of three tributaries to the Boulder River in the study area; bed sediments and waters draining from the Buckeye mine have also been implicated. Geochemical analysis of 35 tailings cores and six bed-sediment samples was undertaken to determine the concentrations of Ag, As, Cd, Cu, Pb,and Zn present in these materials. These elements are environmentally significant, in that they can be toxic to fish and/or the invertebrate organisms that constitute their food. A suite of one-inch cores of dispersed flotation-mill tailings and underlying premining material was taken from a large, flat area north of Basin Creek near the site of the Buckeye mine. Thirty-five core samples were taken and divided into 204 subsamples. The samples were analyzed by ICP-AES (inductively coupled plasma-atomic emission spectroscopy) using a mixed-acid digestion. Results of the core analyses show that the elements listed above are present at moderate to very high concentrations (arsenic to 63,000 ppm, silver to 290 ppm, cadmium to 370 ppm, copper to 4,800 ppm, lead to 93,000 ppm, and zinc to 23,000 ppm). Volume calculations indicate that an estimated 8,400 metric tons of contaminated material are present at the site. Six bed-sediment samples were also subjected to the mixed-acid total digestion, and a warm (50°C) 2M HCl-1% H 2 O 2 leach and analyzed by ICP-AES. Results indicate that bed sediments of Basin Creek are only slightly impacted by past mining above the Buckeye-Enterprise complex, moderately impacted at the upper (eastern) end of the tailings area, and heavily impacted at the lower (western) end of the area and downstream. The metals are mostly contained in the 2M HCl-1% H 2 O 2 leachable phase, which are the hydrous amorphous iron- and manganese-hydroxide coatings on detrital sediment particles.

Montana↗

USGS1999

Organic compounds and trace elements in the Pocomoke River and tributaries, Maryland

In response to concern about recent blooms of the dinoflagellate, Pfiesteria piscicida, samples of sediment and water were collected from the lower Pocomoke River Basin and were screened for trace elements, pesticides, and other organic compounds. A large group of steroid and fatty acid methyl-ester compounds was detected in streamwater using gas chromatography/mass spectroscopy in scan mode. Some of these steroid compounds have been identified and further quantified in bed-sediment extracts. Spatial patterns of the concentrations of cholesterol suggest that these compounds are linked to the runoff of animal wastes into the river. Many of the organic compounds found in the Pocomoke River sediments have not yet been identified, but at least several are in the class of hormone compounds related to estradiols and have the potential to promote endocrine-disrupting effects in aquatic life. Particulate forms of arsenic and zinc are slightly elevated above normal levels for streams, but the sources for these elements are still undetermined. Several pesticides were found in low, parts-per-trillion concentrations, but were within the ranges commonly found in streams of this region.

Maryland↗

USGS2006

Constraints on the age and provenance of the Chugach accretionary complex from detrital zircons in the Sitka Graywacke near Sitka, Alaska

The Sitka Graywacke is the westernmost and youngest unit of the Chugach accretionary complex in southeastern Alaska. Using laser-ablation inductively coupled plasma mass spectroscopy, we obtained 492 detrital-zircon ages on seven typical samples of Sitka Graywacke turbidites, which were collected in a transect across much of the unit near Sitka, Alaska. Individual grains range in age from 66 to 1,802 m.y. The youngest peak ages on relative-probability plots of the western four samples (74, 72, 74, and 74 m.y., from west to east) are distinctly younger than the youngest peak ages of the eastern three samples (105, 103, and 97 m.y., from west to east). These youngest peak ages set maximum depositional ages for each sample. We suggest that these peak ages are not significantly older (within ~5 m.y.) than the depositional age of the Sitka Graywacke because the deposits accumulated in a trench along a convergent margin, where magmatic sources likely continuously introduced juvenile zircons. The differences in the youngest cluster of detrital-zircon ages between the eastern and western sample localities is likely due to both a change in provenance and a fault. The similarity of the youngest peak ages in the Sitka Graywacke to fossil ages in the Valdez Group, in Prince William Sound, implies that the western part of the Sitka Graywacke is correlative with the Valdez Group, as previously inferred. However, the eastern part of the Sitka Graywacke has youngest detrital-zircon ages older than fossil ages in the Valdez Group and younger than fossil ages in the McHugh Complex, which in south-central Alaska is the oldest part of the accretionary complex. The age distribution of zircons in the older, eastern sequence suggests sources along the British Columbia margin. The detrital-zircon ages in the younger, western sequence are similar to igneous ages from south-central Alaska to southern British Columbia. Right-lateral strike slip on various fault systems inboard of the Sitka Graywacke implies that it lay to the south when it was deposited and offscraped. Thus, although source areas as far north as the St. Elias Mountains and south-central Alaska are possible, they were most likely in coastal and interior British Columbia.

Professional Paper↗

USGS2007

Integrated geoscience studies in the Greater Yellowstone Area - Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem

Yellowstone National Park, rimmed by a crescent of older mountainous terrain, has at its core the Quaternary Yellowstone Plateau, an undulating landscape shaped by forces of volcanism, tectonism, and later glaciation. Its spectacular hydrothermal systems cap this landscape. From 1997 through 2003, the United States Geological Survey Mineral Resources Program conducted a multidisciplinary project of Yellowstone National Park entitled Integrated Geoscience Studies of the Greater Yellowstone Area, building on a 130-year foundation of extensive field studies (including the Hayden survey of 1871, the Hague surveys of the 1880s through 1896, the studies of Iddings, Allen, and Day during the 1920s, and NASA-supported studies starting in the 1970s—now summarized in USGS Professional Paper 729 A through G) in this geologically dynamic terrain. The project applied a broad range of scientific disciplines and state-of-the-art technologies targeted to improve stewardship of the unique natural resources of Yellowstone and enable the National Park Service to effectively manage resources, protect park visitors from geologic hazards, and better educate the public on geologic processes and resources. This project combined a variety of data sets in characterizing the surficial and subsurface chemistry, mineralogy, geology, geophysics, and hydrothermal systems in various parts of the park. The sixteen chapters presented herein in USGS Professional Paper 1717, Integrated Geoscience Studies in the Greater Yellowstone Area—Volcanic, Tectonic, and Hydrothermal Processes in the Yellowstone Geoecosystem , can be divided into four major topical areas: (1) geologic studies, (2) Yellowstone Lake studies, (3) geochemical studies, and (4) geophysical studies. The geologic studies include a paper by Ken Pierce and others on the influence of the Yellowstone hotspot on landscape formation, the ecological effects of the hotspot, and the human experience and human geography of the greater Yellowstone ecosystem as influenced by the Yellowstone hotspot. Another paper by Paul Carrara describes the recent movement of a large landslide block dated by tree-ring analyses in the Tower Falls area. The section under Yellowstone Lake studies begins with a classic paper by J. David Love and others on ancestral Lake Yellowstone. Other papers in this section include results and interpretation of the high-resolution bathymetric, seismic reflection, and submersible studies by Lisa Morgan and others. Ken Pierce and others describe results from their studies of shorelines along Yellowstone Lake and their interpretation of inflation-deflation cycles, tilting, and faulting in the Yellowstone caldera. The influence of sublacustrine hydrothermal vent fluids on the geochemistry of Yellowstone Lake is described by Laurie Balistrieri and others. In Pat Shanks and others’ chapter, hydrothermal reactions, stable-isotope systematics, sinter deposition, and spire formation are related to the geochemistry of sublacustrine hydrothermal deposits in Yellowstone Lake. The geochemical studies section considers park-wide geochemical systems in Yellowstone National Park. In Bob Rye and Alfred Truesdell’s paper, the question of recharge to the deep thermal reservoir underlying the geysers and hot springs of Yellowstone National Park is discussed. Irving Friedman and Dan Norton report on the chloride flux emissions from Yellowstone in their paper questioning whether Yellowstone is losing its steam. Wildlife issues as addressed by examining trace-element and stable-isotope geochemistry are discussed in a chapter by Maurice Chaffee and others. In another chapter by Chaffee and others, natural and anthropogenic anomalies and their potential impact on the environment using geochemistry is reported. Pam Gemery-Hill and others present geochemical data for selected rivers, lake waters, hydrothermal vents, and subaerial geysers for the time interval of 1996–2004. The life cycle of gold deposits near the northeast corner of the park is discussed by Brad Van Gosen. Under the geophysical studies segment, Ray Kokaly and others use AVIRIS (Airborne Visible and Infrared Spectroscopy) data to map vegetation cover and microbial communities in Yellowstone National Park. Eric Livo and others report their results using AVIRIS data on hydrothermally altered rock and hot-spring deposits. In his final paper following a half century of scientific research, Irving Friedman presents data on monitoring changes in geothermal activity at Norris Geyser Basin using satellite telemetry. These papers summarize a near-decade-long effort by the USGS from the late 1990s to mid-2000s. In 2001, the USGS in cooperation with the National Park Service (Yellowstone National Park) and the University of Utah established the Yellowstone Volcano Observatory, the 5th volcano observatory in the United States.

Professional Paper↗

USGS2008

Chlorine degassing during the lava dome-building eruption of Mount St. Helens, 2004-2005

Remote measurements of volcanic gases from the Mount St. Helens lava dome were carried out using OpenPath Fourier-Transform Infrared spectroscopy on August 31, 2005. Measurements were performed at a site ~1 km from the lava dome, which was used as a source of IR radiation. On average, during the period of measurement, the volcanic gas contained 99 mol percent H 2 O, 0.78 percent CO 2 , 0.095 percent HCl, 0.085 percent SO 2 , 0.027 percent HF, 4.8×10 -4 percent CO, and 2.5×10 -4 percent COS close to the active vent. The fluxes of these species, constrained by synchronous measurements of SO 2 flux, were 7,200 t/d H 2 O, 140 t/d CO 2 , 22 t/d SO 2 , 14 t/d HCl, 2.0 t/d HF, 54 kg/d CO, and 59 kg/d COS, ±20 percent. Observations of H 2 O/Cl in the vapor and melt are compared to models of closed- and open-system degassing and to models where a closed system dominates to depths as shallow as ~1 km, and gases are then allowed to escape through a permeable bubble network. Although several features are consistent with this model--for example, (1) H 2 O/Cl in the gases emitted from stagnant parts of the lava dome, (2) the concentration of Cl in the matrix glass of erupted dacite, and (3) the glass H 2 O/Cl--the gases emitted from the active part of the lava dome have much higher H 2 O/ Cl than expected. These higher H 2 O/Cl levels result from a combination of two factors (1) the addition of substantial amounts of ground water or glacier-derived H 2 O to the gases at shallow depths, such that only ~10 mol percent of the measured H 2 O is magmatic, and (or) (2) some Cl present as alkali chloride (NaCl and KCl) in the gas phase. The mean molar Cl/S is similar to gases measured at other silicic subductionzone volcanoes during effusive activity; this may be due to the influence of Cl in the vapor on S solubility in the melt, which produces a solubility maximum for S at vapor Cl/S ~1.

Washington↗

USGS2023

Groundwater chemistry and hexavalent chromium

Water samples collected by the U.S. Geological Survey from more than 100 wells between March 2015 and November 2017 in Hinkley and Water Valleys, in the Mojave Desert 80 miles northeast of Los Angeles, California, were analyzed for field parameters, major ions, nutrients, and selected trace elements, including hexavalent chromium, Cr(VI). Water from most wells was alkaline and oxic. The pH ranged from 6.9 in water-table wells near recharge areas along the Mojave River to 9.4 in deeper wells farther downgradient in the northern subarea. Hexavalent chromium concentrations measured by ion chromatography using U.S. Environmental Protection Agency Method 218.6 and a version of that method used for detection of Cr(VI) concentrations as low as 0.06 micrograms per liter (μg/L), produced results comparable to field speciation with subsequent analyses by graphite furnace atomic absorption spectroscopy (coefficient of determination, R 2 , of 0.97). Hexavalent chromium concentrations ranged from less than the study reporting level of 0.10 to 2,500 μg/L. The highest concentrations were within the October–December 2015 (Q4 2015) regulatory Cr(VI) plume downgradient from the Hinkley compressor station. Hexavalent chromium concentrations outside the Q4 2015 regulatory Cr(VI) plume were as high as 11 μg/L. Hexavalent chromium concentrations in water from most wells were distributed in a narrow redox potential and pH band within the overlapping chromate ion, CrO 4 2− (aqueous) , and manganese-3, Mn(III) (solid) , stability fields. The redox potential of water from some wells completed in carbonate-rich mudflat/playa deposits approached the more oxic manganese-4, Mn(IV) (solid) , stability field. However, Cr(VI) concentrations in porewater pressure-extracted from Mn(IV)-containing deposits in the eastern subarea did not exceed 3.3 μg/L, and porewater does not appear to be a source of Cr(VI) concentrations greater than this concentration in water from wells in the eastern subarea. On the basis of comparison with California-wide data, Cr(VI) concentrations at the measured pH were higher than expected for uncontaminated water from wells (1) within the Q4 2015 regulatory Cr(VI) plume, (2) within the eastern subarea nominally crossgradient from the Hinkley compressor station and upgradient from the Q4 2015 regulatory Cr(VI) plume, and (3) from shallow wells in the northern subarea downgradient from the leading edge of the Q4 2015 regulatory Cr(VI) plume. Hexavalent chromium concentrations in alkaline water from wells in the northern subarea of Hinkley Valley and in Water Valley were within ranges expected for uncontaminated water elsewhere in California given their pH and trace-element composition. Hexavalent chromium concentrations were higher than expected on the basis of selected trace-element concentrations that co-occur with Cr(VI) in water from wells within the Q4 2015 regulatory Cr(VI) plume and from wells in the eastern and northern subareas near the plume margins. Hexavalent chromium concentrations did not exceed 4 μg/L in water from domestic wells sampled in Hinkley and Water Valleys and were generally within ranges expected for uncontaminated groundwater given their pH and trace-element composition. Interpretations derived from Cr(VI) and pH, and from Cr(VI) and selected trace-element concentrations collected between March 2015 and November 2017 were used within a summative-scale analysis to determine the Cr(VI) plume extent (chapter G). However, Cr(VI) background concentrations (chapter G) were calculated from regulatory data collected from selected wells between April 2017 and January 2018.

California↗

USGS2004

Microbial and dissolved organic carbon characterization of stormflow in the Santa Ana River at Imperial Highway, Southern California, 1999-2002

The Santa Ana River drains about 2,670 square miles of densely populated coastal southern California, near Los Angeles. Almost all the flow in the river, more than 200,000 acre-feet annually, is diverted to ponds where it infiltrates and recharges underlying aquifers pumped to supply water for more than 2 million people. Base flow in the river is almost entirely treated municipal wastewater discharged from upstream treatment plants and, in the past, stormflow was considered a source of high-quality water suitable for use as a source of ground-water recharge that would dilute poorer quality water recharged during base flow. Stormflow in the Santa Ana River at the Imperial Highway diversion contains total coliform bacteria concentrations as high as 3,400,000 colonies per 100 mL (milliliters). Fecal indicator bacteria concentrations, including fecal coliforms, Escherichia coli, and enterococci, were as high as 310,000, 84,000, and 102,000 colonies per 100 mL, respectively. Although concentrations were high owing to urban runoff during the first stormflow of the rainy season, the highest concentrations occurred during the recessional flows of the first stormflow of the rainy season after streamflow returned to pre-storm conditions. Molecular indicators of microbiological organisms in stormflow, including phospholipid fatty acid (PLFA) and genetic data, show that the diversity of the total microbial population decreases during stormflow while fecal indicator bacteria concentrations increase. This suggests that the source of the bacteria must be poorly diverse and dominated by only a few types of bacteria. Although direct runoff of fecal indicator bacteria from urban areas occurs, this process cannot explain the very high concentrations of fecal indicator bacteria in runoff from upstream parts of the basin characterized by urban, agricultural (including more than 300,000 head of dairy cattle), and other land uses. Although other explanations are possible, fecal indicator bacteria concentrations and molecular microbiological data indicate accumulation and extended survival of bacteria in streambed sediments, and subsequent mobilization of those sediments and associated bacteria during stormflow. Both PLFA and genetic data indicate that water from dairy-waste storage ponds was not present during sampled stormflows. This is consistent with the relatively dry conditions and the absence of large stormflows during the study. Dissolved organic carbon (DOC) concentrations in stormflow ranged from 3 to 15.3 mg/L. In general, concentrations increased during stormflow and were distributed across the stormflow hydrograph in a manner similar to that of fecal indicator bacteria. DOC concentrations typically remained high for several days after flow returned to pre-storm conditions. Ultraviolet absorbance, excitation emission spectroscopy, and sequential fractionation of DOC using XAD-8 and XAD-4 resins showed that the composition of DOC changed rapidly during stormflow. Hydrophobic and hydrophilic acids were the largest fraction of DOC composing between 27 and 45 percent and between 24 and 37 percent of the DOC, respectively. The fraction of DOC composed of hydrophobic acids decreased due to urban runoff and increased during the recession of the first stormflow of the rainy season; the hydrophilic-acid fraction generally decreased throughout the stormflow hydrograph; the transhydrophilic-acid fraction did not vary greatly during stormflow; and the hydrophobic-neutral fraction increased from low values in base flow to almost 30 percent of the DOC after more soluble and more mobile hydrophobic and hydrophilic acids were washed from urban areas. Comparison of ultraviolet absorbance data with data collected during previous studies shows that the optical properties and, presumably, the composition of the DOC were different in this study than DOC collected during wetter periods. Samples of shallow ground water collec

California↗

USGS2005

Remote sensing for environmental site screening and watershed evaluation in Utah Mine lands: East Tintic mountains, Oquirrh mountains, and Tushar mountains

Imaging spectroscopy-a powerful remote-sensing tool for mapping subtle variations in the composition of minerals, vegetation, and man-made materials on the Earth's surface-was applied in support of environmental assessments and watershed evaluations in several mining districts in the State of Utah. Three areas were studied through the use of Landsat 7 ETM+ and Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data: (1) the Tintic mining district in the East Tintic Mountains southwest of Provo, (2) the Camp Floyd mining district (including the Mercur mine) and the Stockton (or Rush Valley) mining district in the Oquirrh Mountains south of the Great Salt Lake, and (3) the Tushar Mountains and Antelope Range near Marysvale. The Landsat 7 ETM+ data were used for initial site screening and the planning of AVIRIS surveys. The AVIRIS data were analyzed to create spectrally defined maps of surface minerals with special emphasis on locating and characterizing rocks and soils with acid-producing potential (APP) and acid-neutralizing potential (ANP). These maps were used by the United States Environmental Protection Agency (USEPA) for three primary purposes: (1) to identify unmined and anthropogenic sources of acid generation in the form of iron sulfide and (or) ferric iron sulfate-bearing minerals such as jarosite and copiapite; (2) to seek evidence for downstream or downwind movement of minerals associated with acid generation, mine waste, and (or) tailings from mines, mill sites, and zones of unmined hydrothermally altered rocks; and (3) to identify carbonate and other acid-buffering minerals that neutralize acidic, potentially metal bearing, solutions and thus mitigate potential environmental effects of acid generation. Calibrated AVIRIS surface-reflectance data were spectrally analyzed to identify and map selected surface materials. Two maps were produced from each flightline of AVIRIS data: a map of iron-bearing minerals and water having absorption features in the spectral region from 0.35 µ m to 1.35 µ m and a map of minerals (including clays, sulfates, micas, and carbonates) having absorptions in the spectral region from 1.45 µ m to 2.51 µ m. Several methods were used to verify the AVIRIS mapping results, including field checking of selected locations with a portable spectrometer, visual inspection of the AVIRIS reflectance spectra, and X-ray diffraction (XRD) analysis of field samples. The maps of iron-bearing minerals derived from analysis of the visible (VIS) and near-infrared (NIR) regions of the electromagnetic spectrum were shown to be more consistently reliable in indicating the presence of jarosite than were the maps generated from analysis of the short-wave infrared (SWIR) region. When present in abundance, phyllosilicate minerals tend to dominate the SWIR and mask the spectral features of jarosite in that wavelength region. The crystal field absorptions of jarosite in the VIS and NIR spectral regions will commonly be present regardless of whether the Fe-OH absorption feature near 2.27 µ m can be detected. For this reason, the VIS and NIR were preferable to the SWIR for the remote spectroscopic identification of jarosite (and other iron-bearing minerals). Large exposures of unmined hydrothermally altered rocks occur throughout the three study areas. These rocks commonly contain sulfide or sulfate minerals that produce sulfuric acid upon subaerial oxidation. The acid may be introduced into local surface and ground water and thus lower the baseline (that is, the premining) pH for a watershed.

Utah↗

USGS2013

Sources and characteristics of organic matter in the Clackamas River, Oregon, related to the formation of disinfection by-products in treated drinking water

This study characterized the amount and quality of organic matter in the Clackamas River, Oregon, to gain an understanding of sources that contribute to the formation of chlorinated and brominated disinfection by-products (DBPs), focusing on regulated DBPs in treated drinking water from two direct-filtration treatment plants that together serve approximately 100,000 customers. The central hypothesis guiding this study was that natural organic matter leaching out of the forested watershed, in-stream growth of benthic algae, and phytoplankton blooms in the reservoirs contribute different and varying proportions of organic carbon to the river. Differences in the amount and composition of carbon derived from each source affects the types and concentrations of DBP precursors entering the treatment plants and, as a result, yield varying DBP concentrations and species in finished water. The two classes of DBPs analyzed in this study-trihalomethanes (THMs) and haloacetic acids (HAAs)-form from precursors within the dissolved and particulate pools of organic matter present in source water. The five principal objectives of the study were to (1) describe the seasonal quantity and character of organic matter in the Clackamas River; (2) relate the amount and composition of organic matter to the formation of DBPs; (3) evaluate sources of DBP precursors in the watershed; (4) assess the use of optical measurements, including in-situ fluorescence, for estimating dissolved organic carbon (DOC) concentrations and DBP formation; and (5) assess the removal of DBP precursors during treatment by conducting treatability "jar-test" experiments at one of the treatment plants. Data collection consisted of (1) monthly sampling of source and finished water at two drinking-water treatment plants; (2) event-based sampling in the mainstem, tributaries, and North Fork Reservoir; and (3) in-situ continuous monitoring of fluorescent dissolved organic matter (FDOM), turbidity, chlorophyll- a , and other constituents to continuously track source-water conditions in near real-time. Treatability tests were conducted during the four event-based surveys to determine the effectiveness of coagulant and powdered activated carbon (PAC) on the removal of DBP precursors. Sample analyses included DOC, total particulate carbon (TPC), total and dissolved nutrients, absorbance and fluorescence spectroscopy, and, for regulated DBPs, concentrations of THMs and HAAs in finished water and laboratory-based THM and HAA formation potentials (THMFP and HAAFP, respectively) for source water and selected locations throughout the watershed. The results of this study may not be typical given the record and near record amounts of precipitation that occurred during spring that produced streamflow much higher than average in 2010-11. Although there were algal blooms, lower concentrations of chlorophyll- a were observed in the water column during the study period compared to historical data. Concentrations of DBPs in finished (treated) water averaged 0.024 milligrams per liter (mg/L) for THMs and 0.022 mg/L for HAAs; maximum values were about 0.040 mg/L for both classes of DBPs. Although DBP concentrations were somewhat higher within the distribution system, none of the samples collected for this study or for the quarterly compliance monitoring by the water utilities exceeded levels permissible under existing U.S. Environmental Protection Agency (USEPA) regulations: 0.080 mg/L for THMs and 0.060 mg/L for HAAs. DOC concentrations were generally low in the Clackamas River, typically about 1.0-1.5 mg/L. Concentrations in the mainstem occasionally increased to nearly 2.5 mg/L during storms; DOC concentrations in tributaries were sometimes much higher (up to 7.8 mg/L). The continuous in-situ FDOM measurements indicated sharp rises in DOC concentrations in the mainstem following rainfall events; concentrations were relatively stable during summer base flow. Even though the first autumn storm mobilized appreciable quantities of carbon, higher concentrations of DBPs in finished water were observed 3-weeks later, after the ground was saturated from additional rainfall. The majority of the DOC in the lower Clackamas River appears to originate from the upper basin, suggesting terrestrial carbon was commonly the dominant source. Lower-basin tributaries typically contained the highest concentrations of DOC and DBP precursors and contributed substantially to the overall loads in the mainstem during storms. During low-flow periods, tributaries were not major sources of DOC or DBP precursors to the Clackamas River. Although the dissolved fraction of organic carbon contributed the majority of DBP precursors, at times the particulate fraction (inorganic sediment and organic particles including detritus and algal material) contributed a substantial fraction of DBP precursors. Considering just the main-stem sites, on average, 10 percent of THMFP and 32 percent of HAAFP were attributed to particulate carbon. This finding suggests water-treatment methods that remove particles prior to chlorination would reduce finished-water DBP concentrations to some degree. Overall, concentrations of THM and HAA precursors were closely linked to DOC concentrations; laboratory DBP formation potentials (DBPFPs) clearly showed that THMFP and HAAFP were greatest in the downstream tributaries that contained elevated carbon concentrations. However, carbon-normalized "specific" formation potentials for THMs and HAAs (STHMFP and SHAAFP, respectively) revealed changes in carbon character over time that affected the two types of DBP classes differently. HAA precursors were elevated in waters containing aromatic-rich soil-derived material arising from forested areas. In contrast, THM precursors were associated with carbon having a lower aromatic content; highest STHMFP occurred in autumn 2011 in the mainstem from North Fork Reservoir downstream to LO DWTP. This pattern suggests the potential for a link between THM precursors and algal-derived carbon. The highest STHMFP value was measured within North Fork Reservoir, indicating reservoir derived carbon may be important for this class of DBPs. Weak correlations between STHMFP and SHAAFP emphasize that precursor sources for these types of DBPs may be different. This highlights not only that different locations within the watershed produce carbon with different reactivity (specific DBPFP), but also that different management approaches for each class of DBP precursors could be required for control. Treatability tests conducted on source water during four basin-wide surveys demonstrated that an average of about 40 percent of DOC can be removed by coagulation. While the decrease in THMFP following coagulation was similar to DOC, the decrease in HAAFP was much greater (approximately 70 percent), indicating coagulation is particularly effective at removing HAA precursors'likely because of the aromatic nature of the carbon associated with HAA precursors. Several findings from this study have direct implications for managing drinking-water resources and for providing useful information that may help improve treatment-plant operations. For example, the use of in-situ fluorometers that measure FDOM provided an excellent proxy for DOC concentration in this system and revealed short-term, rapid changes in DOC concentration during storm events. In addition, the strong correlation between FDOM values measured in-situ and HAA5 concentrations in finished water may permit estimation of continuous HAA concentrations, as was done here. As part of this study, multiple in-situ FDOM sensors were deployed continuously and in real-time to characterize the composition of dissolved organic matter. Although the initial results were promising, additional research and engineering developments will be needed to demonstrate the full utility of these sensors for this purpose. In conclusion, although DBPFPs were strongly correlated to DOC concentration, some DBPs formed from particulate carbon, including terrestrial leaf material and algal material such as planktonic species of blue-green algae and sloughed filaments, stalks, and cells of benthic algae. Different precursor sources in the watershed were evident from the data, suggesting specific actions may be available to address some of these sources. In-situ measurements of FDOM proved to be an excellent proxy for DOC concentration as well as HAA formation during treatment, which suggests further development and refinement of these sensors have the potential to provide real-time information about complex watershed processes to operators at the drinking-water treatment plants. Follow-up studies could examine the relative roles that terrestrial and algal sources have on the DBP precursor pool to better understand how watershed-management activities may be affecting the transport of these compounds to Clackamas River drinking-water intakes. Given the low concentrations of algae in the water column during this study, additional surveys during more typical river conditions could provide a more complete understanding of how algae contribute DBP precursors. Further development of FDOM-sensor technology can improve our understanding of carbon dynamics in the river and how concentrations may be trending over time. This study was conducted in collaboration with Clackamas River Water and the City of Lake Oswego water utilities. Other research partners included Oregon Health and Science University in Hillsboro, Oregon, Alexin Laboratory in Tigard, Oregon, U.S. Geological Survey National Research Program Laboratory in Denver, Colorado, and the U.S. Geological Survey Water Science Centers in Portland, Oregon, and Sacramento, California. This project was supported with funding from Clackamas River Water, City of Lake Oswego, the U.S. Geological Survey, and the Water Research Foundation.

Oregon↗