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At least 1,459 records · Page 81Linked to original sources

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Tulare Lake bed area, southern San Joaquin Valley, California, 1986-87

Concentrations of numerous toxic trace elements and pesticides were measured during 1986 in water, sediment, and biota from three areas near the Tulare Lake Bed, southern San Joaquin Valley, California: Kern National Wildlife Refuge, Pixley National Wildlife Refuge, and Westfarmers evaporation ponds about 5 mi west of Kern National Wildlife Refuge, to determine whether toxic constituents in agricultural-irrigation drainage pose a threat to beneficial uses of water, especially to uses by wildlife. Pesticide residues were found to be low at all three areas. Trace element concentrations were found to be comparatively low at the Kern and Pixley National Wildlife Refuge areas and high at the Westfarmers evaporation ponds. Dissolved selenium concentrations were < 1 micrograms/L (ug/L) in areas on and adjacent to the refuges, but ranged from 110 to 360 ug/L in the saline drainwater impounded in the evaporation ponds. The ratio of mean selenium concentrations in biota from Westfarmers ponds compared to biota from Kesterson National Wildlife Refuge (where adverse effects have been documented) is 5 for waterboatman, 2 for avocet liver, 1 for avocet eggs, and < 1 for widgeongrass. The low concentrations measured at Kern and Pixley National Wildlife Refuges suggest that trace elements and pesticides pose little threat to wildlife there; however, impounded subsurface drainage from agricultural irrigation does pose a threat to wildlife at the nearby Westfarmers ponds. Preliminary results of surveys conducted in 1987 indicated that there are adverse biological effects on shorebirds nesting at the ponds, although interpretation of the magnitude of the effects is premature, pending completion of ongoing studies by the U.S. Fish and Wildlife Service. (Author 's abstract)

Water-Resources Investigations Report↗

Hydrology of Crater, East and Davis Lakes, Oregon; with section on Chemistry of the Lakes

Crater, East, and Davis Lakes are small bodies of fresh water that occupy topographically closed basins in Holocene volcanic terrane. Because the annual water supply exceeds annual evaporation, water must be lost by seepage from each lake. The seepage rates vary widely both in volume and in percentage of the total water supply. Crater Lake loses about 89 cfs (cubic feet per second), equivalent to about 72 percent of its average annual supply. East Lake loses about 2.3 cfs, or about 44 percent of its estimated supply. Davis Lake seepage varies greatly with lake level, but the average loss is about 150 cfs, more than 90 percent of its total supply. The destination of the seepage loss is not definitely known for any of the lakes. An approximate water budget was computed for stationary level for each lake, by using estimates 'by the writer to supplement the hydrologic data available. The three lake waters are dilute. Crater Lake contains about 80 ppm, (parts per million) of dissolved solids---mostly silica, sodium, and bicarbonate, and lesser amounts of calcium, sulfate, and chloride. Much of the dissolved-solids content of Crater Lake---especially the sulfate and chloride---may be related to fumarole and thermal-spring activity that presumably followed the collapse of Mount Mazama. Although Grater Lake loses an estimated 7,000 tons of its 1.5million-ton salt content each year by leakage, the chemical character of the lake did not change appreciably between 1912 and 1964. East Lake contains 200 ppm of dissolved solids, which includes major proportions of calcium, sodium, bicarbonate, and sulfate, but almost no chloride. The lake apparently receives much of its dissolved solids from subsurface thermal springs. Annual solute loss from East Lake by leakage is about 450 tons, or 3 percent of the lake's 15,000-ton estimated solute content. Davis Lake contains only 48 ppm of dissolved solids, much of which is silica and bicarbonate; chloride is almost completely absent. Approximate physical and hydrologic data for the lakes are summarized in the following table. [Table]

Water Supply Paper↗

Program for monitoring the chemical quality of ground water in Utah – Summary of data collected through 1984

The U.S. Geological Survey formally started a program for monitoring ground-water quality in Utah during 1957 in cooperation with the State of Utah. Most observation wells in the monitoring network are privately owned. Initially, the network consisted of fewer than 50 wells; by 1984, however, it had expanded to include more than 200 wells. Chemical analyses are available for water from some of the wells from as early as 1927, long before those wells were formally added to the network. The monitoring program was initiated to detect any changes in chemical quality that might be associated with the withdrawal of water from wells. Dissolved-solids concentrations in water samples collected from the observation wells through 1984 ranged from 92 to 19,000 milligrams per liter. An observation well in the Uinta Basin yielded the sample with the smallest dissolved-solids concentration, and another well in the Uinta Basin yielded the sample with the largest dissolved-solids concentration. There was a progressive increase in salinity of water produced by several of the observation wells in Pahvant Valley and in the Milford and Beryl-Enterprise areas. The increases in salinity occurred during 1950-84, coinciding with the decline of water levels due to pumping for irrigation. Water-quality changes related either to ground-water withdrawals or ground-water recharge also were detected in several other areas, including Curlew Valley, Cedar City Valley, Northern Utah Valley, the lower Bear River valley, and the Sevier Desert. Water produced from wells in Goshen Valley and the upper Fremont River valley had short term increases in chloride, sulfate, and dissolved-solids concentrations, indicating possible local contamination of the ground water. Also, since the late 1950's, dissolved-solids concentrations have increased in water produced by a well completed in the principal aquifer in Salt Lake Valley downgradient from areas where extensive use has been made of road salt.

Utah↗

Relation of shallow water quality in the Central Oklahoma Aquifer to geology, soils, and land use

The purpose of this report is to identify, describe, and explain relations between natural and land-use factors and ground-water quality in the Central Oklahoma aquifer NAWQA study unit. Natural factors compared to water quality included the geologic unit in which the sampled wells were completed and the properties of soils in the areas surrounding the wells. Land-use factors included types of land use and population densities surrounding sampled wells. Ground-water quality was characterized by concentrations of inorganic constituents, and by frequencies of detection of volatile organic compounds and pesticides. Water-quality data were from samples collected from wells 91 meters (300 feet) or less in depth as part of Permian and Quaternary geologic unit survey networks and from an urban survey network. Concentrations of many inorganic constituents were significantly related to geology. In addition, concentrations of many inorganic constituents were greater in water from wells from the Oklahoma City urban sampling network than in water from wells from low-density survey networks designed to evaluate ambient water quality in the Central Oklahoma aquifer study unit. However, sampling bias may have been induced by differences in hydrogeologic factors between sampling networks, limiting the ability to determine land-use effects on concentrations of inorganic constituents. Frequencies of detection of pesticide and volatile organic compounds (VOC's) in ground-water samples were related to land use and population density, with these compounds being more frequently detected in densely-populated areas. Geology and soil properties were not significantly correlated to pesticide or VOC occurrence in ground water. Lesser frequencies of detection of pesticides in water from wells in rural areas may be due to low to moderate use of those compounds on agricultural lands in the study unit, with livestock production being the primary agricultural activity. There are many possible sources of pesticides and VOC's in the urban areas of Central Oklahoma. Because only existing water-supply wells were sampled, it is not clear from the data collected whether pesticides and VOC's: (1) occur in low concentrations throughout upper portions of the aquifer in urban areas, or (2) are present in ground water only in the immediate vicinity of the wells due to back-flow of those chemicals into the wells or to inflow around cement seals and through gravel packs surrounding well casings of surface runoff containing those compounds.

Oklahoma↗

Water-quality data analysis of the upper Gunnison River watershed, Colorado, 1989-99

Water-quality data from October 1969 to December 1999 for both surface water and ground water in the upper Gunnison River watershed were retrieved and compiled from the U.S. Geological Survey National Water Information System and the U.S. Environmental Protection Agency Storage and Retrieval databases. Analyses focused primarily on a subset of these data from October 1989 to December 1999. The upper Gunnison River watershed is located west of the Continental Divide in the Southern Rocky Mountains physiographic province. Surface-water-quality data were compiled for 482 sites in the upper Gunnison River watershed. Most values of surface-water temperature, dissolved oxygen, and pH were within Colorado Department of Public Health and Environment (CDPHE) in-stream standards. Calcium bicarbonate type water was the most spatially dominant water type in the basin. Nutrients were most commonly sampled along the Slate River and East River near Crested Butte and along the Gunnison River from the confluence of the East and Taylor Rivers to the western edge of the watershed. Median ammonia concentrations were low, with many concentrations less than laboratory reporting levels. All nitrate concentrations met the CDPHE in-stream standard of 10 milligrams per liter. More than 30 percent of stream sites with total phosphorus data (23 of 61 sites) had concentrations greater than the U.S. Environmental Protection Agency (USEPA) recommendation for controlling eutrophication. Ammonia concentrations at a site on the Slate River near Crested Butte had a statistically significant upward trend for the 1995–99 period. The Slate River near Crested Butte site is located immediately downstream from the towns of Crested Butte and Mount Crested Butte and may reflect recent population growth or other land-use changes. However, the rate of change of the trend is small (0.017 milligram per liter per year). Although a multiple comparison test showed nitrate concentrations were statistically different between agriculture and forest sites and between agriculture and urban land-use classified sites, median concentrations were low among all land-use settings. Median concentrations of total phosphorus were greatest in rangeland areas and least in urban areas. No significant differences were identified for median concentrations of total phosphorus in agriculture and forest land-use areas. Median concentrations of arsenic, lead, mercury, selenium, and silver were low or below reporting levels throughout the watershed. Aluminum, cadmium, copper, lead, manganese, and zinc concentrations were elevated near the town of Crested Butte and on Henson Creek upstream from Lake City, which may be explained by upstream areas of historical mining. Samples for six trace elements exceeded standards: cadmium, copper, lead, manganese, silver, and zinc. A downward trend (3 micrograms per liter per year) was identified for the dissolved iron concentration at a site on the Gunnison River at County Road 32 downstream from the city of Gunnison. Streambed-sediment samples from areas affected by historical mining also had elevated concentrations of some trace elements. Chlorophyll- a concentrations in samples from Blue Mesa Reservoir and streams in the Crested Butte and Gunnison areas were typical of unenriched to moderately enriched conditions. Median concentrations of 5-day biochemical oxygen demand concentrations for sites between Crested Butte and Blue Mesa Reservoir were less than 2 milligrams per liter. Occasional high (greater than 200 counts per 100 milliliters) concentrations for fecal coliform were determined at selected sites within the study area. However, median concentrations were less than 100 counts per 100 milliliters except for the Squaw Creek and Cimarron River areas in the western part of the watershed. Ground-water-quality data have been collected by the U.S. Geological Survey from 99 wells. Many wells were completed in aquifers composed of Holocene-age valley fill and alluvium. Most field properties were within the USEPA Secondary Drinking Water Regulations (SDWR) range for treated drinking water, except for 2 (of 40) pH samples. Calcium bicarbonate was the predominant water type in nearly all aquifers except for the aquifers composed of volcanic rock, which had more sodium and sulfate mixed water types. Wells with sulfate concentrations exceeding the SDWR of 250 milligrams per liter were completed in aquifers composed of volcanic rock near Lake City. Dissolution and oxidation of sulfide minerals in these aquifers may explain the elevated sulfate concentrations in ground water at these locations. Nutrient concentrations in ground water were generally low, and median concentrations for ammonia, nitrite, and dissolved phosphorus were below reporting levels. All nitrate concentrations in the samples were below the USEPA drinking-water maximum contaminant level of 10 mg/L. No statistical difference was found in nitrate concentrations among the four land-use classifications (agriculture, forest, rangeland, and urban). Trace elements in ground water were generally below the USEPA SDWR. Three iron samples exceeded the USEPA SDWR of 300 micrograms per liter at two wells located near the city of Gunnison and at a well south of the town of Powderhorn near the Cebolla River. Nine of 39 manganese samples exceeded the USEPA SDWR of 50 micrograms per liter and were collected from aquifers composed of Holocene-age valley fill and alluvium near Gunnison and Crested Butte and in one well near the Cebolla River. Radon gas is a natural radioactive decay product of uranium. All 39 radon samples collected from ground water in the watershed exceeded the proposed USEPA drinking-water maximum contaminant level of 300 picocuries per liter and ranged from 426 to 3,830 picocuries per liter.

Colorado↗

ECCOE Landsat quarterly Calibration and Validation report—Quarter 3, 2022

Executive Summary The U.S. Geological Survey Earth Resources Observation and Science Calibration and Validation (Cal/Val) Center of Excellence (ECCOE) focuses on improving the accuracy, precision, calibration, and product quality of remote-sensing data, leveraging years of multiscale optical system geometric and radiometric calibration and characterization experience. The ECCOE Landsat Cal/Val Team continually monitors the geometric and radiometric performance of active Landsat missions and makes calibration adjustments, as needed, to maintain data quality at the highest level. This report provides observed geometric and radiometric analysis results for Landsats 7–8 for quarter 3 (July–September) of 2022. All data used to compile the Cal/Val analysis results presented in this report are freely available from the U.S. Geological Survey EarthExplorer website: https://earthexplorer.usgs.gov . One specific activity that the ECCOE Landsat Cal/Val Team closely monitored was the lowering of the Landsat 7 orbit. On April 6, 2022, the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) sensor was placed into standby mode, and a series of spacecraft burns was completed through the month of April to lower the satellite’s orbit by 8 kilometers. Imaging resumed at a lower orbit of 697 kilometers on May 5, 2022, extending the science mission to allow for essential data acquisition during the 2022 Northern Hemisphere fire and growing season. Additional information about the Landsat 7 orbit lowering is here: https://www.usgs.gov/centers/eros/news/landsat-7-lowered-standard-landsat-orbit#:~:text=The%20satellite's%20primary%20science%20mission%20has%20ended&text=On%20April%206%2C%202022%2C%20the,satellite's%20orbit%20by%208%20kilometers .

Open-File Report↗

Hydrologic monitoring of a waste-injection well near Milton, Florida, June 1975 - December 1976

This report presents the hydraulic and chemical data collected from June 1, 1975 to December 31, 1976 through a monitoring program at a deep-well waste-injection system at the American Cyanamid Company's plant near Milton, Florida. The injection system consists of a primary injection well, a standby injection well, and two deep monitor wells all completed open hole in the lower limestone of the Floridan aquifer and one shallow-monitor well completed in the upper limestone of the Floridan aquifer. Two of the monitor wells and the standby injection well are used to observe hydraulic and geochemical effects of waste injection in the injection zone at locations 1,025 feet southwest, 1,560 feet south, and 1.55 miles northeast of the primary injection well. The shallow-monitor well, used to observe any effects in the first permeable zone above the 200-foot-thick confining bed, is 28 feet north of the primary injection well.

Florida↗

Sampling design workflows and tools to support adaptive monitoring and management

On the Ground • Adaptive land management requires monitoring of resource conditions, which requires choices about where and when to monitor a landscape. • Designing a sampling design for a monitoring program can be broken down in to eight steps: identifying questions, defining objectives, selecting reporting units, deciding data collection methods, defining the sample frame, selecting an appropriate design type, deciding stratification and allocation, and identifying the required sampling effort. • Here, we provide descriptions of each step in the process and identify tools and resources to complete each step.

Rangelands↗

Radar and photoclinometric studies of wrinkle ridges on Mars

Earth-based radar altimetry and image derived photoclinometric profiles were analyzed to examine both the long- and short-wavelength topography associated with wrinkle ridges on Mars. Photoclinometrically derived elevation data across wrinkle ridges were evaluated to determine the sensitivity of profiles to two empirical photoclinometric parameters, the horizontal digital number (HDN) and the scattered light value (SLV). The photoclinometric profiles are extremely sensitive to small variations in HDN. The sense of slope of a profile can be completely reversed over a range in HDN of as little as ±1. Comparably small variations in the SLV have relatively minor effects on the photoclinometrically derived elevations. The existence of elevation offsets from one side of the ridge to the other, reported in previous photoclinometric studies of martian wrinkles, were not confirmed through photoclinometry. In addition, no evidence of elevation offsets were found in Earth-based radar altimetry profiles across wrinkle ridges. In order to more accurately model wrinkle ridge topography, we controlled photoclinometrically derived elevations with long-wavelength topography obtained from the radar altimetry. The results of this study do not support kinematic models for the origin of planetary wrinkle ridges that involve deeply rooted thrust faults which separate crustal blocks at different elevations. A kinematic model involving buckling of shallow crustal layers into concentric folds that close, leading to the development of thrust faults, is consistent with wrinkle ridge morphology and terrestrial analogs. Recent geophysical studies of terrestrial analogs and the influence of shallow subsurface structures, particularly buried craters, on the localization of many wrinkle ridges on Mars suggest that thrust faults associated with the ridges are confined to the ridged plains material and do not extend into the lithosphere.

Journal of Geophysical Research E: Planets↗

Potential threats facing a globally important population of the magnificent frigatebird Fregata magnificens

Tracking of seabirds has been used to identify foraging hotspots, migratory routes and to assess at-sea threats facing populations. One such threat is the potential negative interaction between seabirds and fisheries through incidental by-catch. In 2012, 60 magnificent frigatebirds Fregata magnificens were found dead, entangled in fishing line, at the globally important breeding site in the British Virgin Islands (BVI). To assess the potential relationship between foraging behaviour and fishing activity, data loggers were deployed on breeding magnificent frigatebirds to record foraging movements. In addition, a survey of local fishers was conducted to assess the scale of incidental by-catch. We recorded 28 complete foraging trips from GPS and GPS-GSM loggers, and 1758 PTT locations. Birds travelled up to 3.3–1067 km from their breeding colony and entered the waters of 10 neighbouring territories. A high percentage of fishers (93% n = 28) reported catching at least one seabird annually, of which the most common were magnificent frigatebirds and brown boobies Sula leucogaster . There are estimated to be at least 1112 vessels in the recreational and artisanal fishing fleets of BVI and its neighbouring islands. Thus, this substantial fishery may have potentially profound effects on seabird populations in the region.

Tropical Zoology↗

Systematic catalogue of vertebrata of the Eocene of New Mexico, collected in 1874

The present essay completes the determination of the species of vertebrata obtained by the geographical survey under your charge in the Eocene formation of New Mexico during the field-season of 1874. The descriptions which have already appeared in your [George M. Wheeler] report to the Chief of Engineers, as published in the annual report of the latter for 1874, are not now repeated. The total number of mammalia is forty-seven species, of which the present report introduces twenty-four for the first time.

Monograph↗

Regional Studies of the Potwar Plateau Area, Northern Pakistan

The papers in this volume are products of a cooperative program between the Geological Survey of Pakistan (GSP) and the U.S. Geological Survey (USGS), sponsored by the Government of Pakistan and the U.S. Agency for International Development. The focus of the program, the Coal Resources Exploration and Assessment Program (COALREAP), was to explore and assess Pakistan?s indigenous coal resources. As part of COALREAP, GSP and USGS geologists conducted regional geologic studies from 1988 to 1991 of the coal-bearing areas in the Potwar region of northern Pakistan. A reference section was selected from which to obtain faunal and floral analyses. The composite sections at Nammal Pass and Nammal Dam served as the basis for this regional reference. Although this Bulletin 2078 is being released in 2007, the writing and technical reviews were completed in 1993, and the chapters reflect the work done until that time. During the long production process for the Bulletin, which ultimately resulted in the oversize plates being digitized, the scientific content of the chapters was not changed, and most reports published since 1993 were not cited. A change in the age of the Patala Formation is discussed below [in the full preface], but the age discussions and illustrations in the chapters were not updated.

Bulletin↗

Alaska Geochemical Database (AGDB)-Geochemical data for rock, sediment, soil, mineral, and concentrate sample media

The Alaska Geochemical Database (AGDB) was created and designed to compile and integrate geochemical data from Alaska in order to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, environmental impact assessments, and studies in medical geology. This Microsoft Access database serves as a data archive in support of present and future Alaskan geologic and geochemical projects, and contains data tables describing historical and new quantitative and qualitative geochemical analyses. The analytical results were determined by 85 laboratory and field analytical methods on 264,095 rock, sediment, soil, mineral and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed in USGS laboratories or, under contracts, in commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects from 1962 to 2009. In addition, mineralogical data from 18,138 nonmagnetic heavy mineral concentrate samples are included in this database. The AGDB includes historical geochemical data originally archived in the USGS Rock Analysis Storage System (RASS) database, used from the mid-1960s through the late 1980s and the USGS PLUTO database used from the mid-1970s through the mid-1990s. All of these data are currently maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB were used to generate most of the AGDB data set. These data were checked for accuracy regarding sample location, sample media type, and analytical methods used. This arduous process of reviewing, verifying and, where necessary, editing all USGS geochemical data resulted in a significantly improved Alaska geochemical dataset. USGS data that were not previously in the NGDB because the data predate the earliest USGS geochemical databases, or were once excluded for programmatic reasons, are included here in the AGDB and will be added to the NGDB. The AGDB data provided here are the most accurate and complete to date, and should be useful for a wide variety of geochemical studies. The AGDB data provided in the linked database may be updated or changed periodically. The data on the DVD and in the data downloads provided with this report are current as of date of publication.

Data Series↗

ECCOE Landsat Quarterly Calibration and Validation report—Quarter 2, 2022

Executive Summary The U.S. Geological Survey Earth Resources Observation and Science Calibration and Validation (Cal/Val) Center of Excellence (ECCOE) focuses on improving the accuracy, precision, calibration, and product quality of remote-sensing data, leveraging years of multiscale optical system geometric and radiometric calibration and characterization experience. The ECCOE Landsat Cal/Val Team continually monitors the geometric and radiometric performance of active Landsat missions and makes calibration adjustments, as needed, to maintain data quality at the highest level. This report provides observed geometric and radiometric analysis results for Landsats 7–8 for quarter 2 (April–June), 2022. All data used to compile the Cal/Val analysis results presented in this report are freely available from the U.S. Geological Survey EarthExplorer website: https://earthexplorer.usgs.gov . One specific activity that the ECCOE Landsat Cal/Val Team closely monitored was the lowering of the Landsat 7 orbit. On April 6, 2022, the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) sensor was placed into standby mode, and a series of spacecraft burns was completed throughout the month of April to lower the satellite’s orbit by 8 kilometers. Imaging resumed at the lower orbit of 697 kilometers on May 5, 2022, extending the science mission to allow for essential data to be acquired during the 2022 Northern Hemisphere fire and growing season. Additional information about the Landsat 7 orbit lowering is here: https://www.usgs.gov/centers/eros/news/landsat-7-lowered-standard-landsat-orbit#:~:text=The%20satellite's%20primary%20science%20mission%20has%20ended&text=On%20April%206%2C%202022%2C%20the,satellite's%20orbit%20by%208%20kilometers .

Open-File Report↗

Correlative estimates of streamflow in the upper Colorado River basin

Most hydrologic analyses, whether for appraisal of the water resource, feasibility of a particular development, design of a system of operation, assessment of gains or losses from acts of man or natural changes, or almost any other use, require the extension in time of some streamflow records. In the Upper Colorado River Basin, streamflow records have been extended by various agencies from time to time to fulfill their individual needs, resulting in different estimates of flow for the same point and time. The purpose of this report is to provide correlative estimates of monthly mean discharge at discontinued streamflow gaging stations so that all users will have access to a single set of data. Estimates of monthly mean discharge for periods other than the period of actual record are given for certain discontinued streamflow gaging stations. The stations selected were discontinued in recent years, but they have a sufficient length of record to permit development of a meaningful correlation with the records for a nearby long-term gaging station. Where possible, estimates of monthly mean discharge are made to provide a complete record, estimated or measured, from 1930 to 1965. However, where the long-term gaging station record encompasses a shorter period, the estimates cover only that shorter period. Estimates for periods prior to 1930 were not made, although these may be computed for a few stations. Lack of a related long-term gaging-station record prevented the extension of records at many discontinued stations. The area covered in this report (fig. 1) is that defined in the Colorado River Compact of 1922, as the Upper Basin "those parts of the States of Arizona, Colorado, New Mexico, Utah, and Wyoming within and from which waters naturally drain into the Colorado River System above Lee Ferry," 1 but excluding "all parts of said States located without the drainage area of the Colorado River System which are now and shall hereafter be beneficially served by waters diverted from the System above Lee Ferry" (Wilbur and Ely, 1948, p. A18).

Colorado River Basin↗

Radiocarbon dates from the Hawaiian Islands: A compilation

Radiocarbon dating has proved to be a useful tool for the correlation of events and their timing during the Quaternary. In the Hawaiian Islands, the application of this technique is providing a chronology of the geologic history that will serve as a framework for studies of volcanologic and related hazards, sea-level changes, paleomagnetism, and paleobotany. Many 14 C dates have also been determined for archaeological studies on the Islands. During the last 3 years, the U.S. Geological Survey (USGS) radiocarbon laboratory at Reston, VA, has determined more than 100 14 C dates from carbonized roots and other plant material collected from beneath prehistoric lava flows and ash deposits from Mauna Loa and Kilauea volcanoes. Prior to 1976, only 10 flows from these volcanoes had been dated by radiocarbon methods. Collection of dateable material has been facilitated by an improved understanding of the conditions of charcoal formation and preservation beneath basaltic lavas (Lockwood and Lipman, 1979). The purpose of this report is to gather all published Hawaiian radiocarbon dates, except geochemical dates, together in order to spare those working on the geologic and archaeologic history of the Islands the time and energy necessary to recover these dates from their various sources, as well as to prevent duplication of effort in the field and laboratory. A few unpublished dates from the Reston laboratory are also included. The listing and bibliography are as complete as possible. The U.S. Geological Survey library was used as the primary source of information. The dates are divided by island, and, within island groups, by category of interest. Within each category, dates are listed chronologically from youngest to oldest. The letter before the lab number tells what lab ran the sample. The list of laboratories gives the addresses.

Hawaii↗

Selected hydrologic data, through water year 1998, Black Hills Hydrology Study, South Dakota

This report presents water-level and water-quality data that have been collected or compiled, through water year 1998, for the Black Hills Hydrology Study. This study is a long-term cooperative effort between the U.S. Geological Survey, the South Dakota Department of Environment and Natural Resources, and the West Dakota Water Development District (which represents various local and county cooperators). This report is the third in a series of project data reports produced for the study. Daily water-level data are presented for 71 observation wells and 2 cave sites in the Black Hills area of western South Dakota. The wells include a network of observation wells that are maintained in cooperation with the South Dakota Department of Environment and Natural Resources and are completed in various bedrock formations that are utilized as aquifers in the Black Hills area of western South Dakota. Both cave sites are located within outcrops of the Madison Limestone. Data presented include site descriptions, hydrographs, and tables of daily water levels. Annual measurements of water levels collected during water years 1995-98 from a net-work of 18 additional, miscellaneous wells are presented. These wells are part of a statewide network of wells completed in bedrock aquifers that was operated from 1959 through 1989 in cooperation with the South Dakota Department of Environment and Natural Resources. Site descriptions and hydrographs for the entire period of record for each site also are presented. Water-quality data are presented for 9 surface-water sites, 19 ground-water sites, and 30 sites that have been classified as areas of surface- and ground-water interaction in the Black Hills area. The surface- and ground-water interaction sites are further divided into three categories that include 11 loss zone sites, 8 headwater spring sites, and 11 downgradient spring sites.

South Dakota↗

Selected hydrologic data, through water year 1994, Black Hills Hydrology Study, South Dakota

This report presents water-level, water-quality, and spring data that have been collected or compiled, through water year 1994, for the Black Hills Hydrology Study. This study is a long-term cooperative effort between the U.S. Geological Survey, the South Dakota Department of Environment and Natural Resources, and the West Dakota Water Development District (which represents various local and county cooperators). This report is the second in a series of biennial project data reports produced for the study. Daily water-level data are presented for 39 observation wells and 2 cave sites in the Black Hills area of western South Dakota. The wells are part of a network of observation wells maintained by the Department of Environment and Natural Resources and are completed in various bedrock formations that are utilized as aquifers in the Black Hills area. Both cave sites are located within outcrops of the Madison Limestone. Data presented include site descriptions, hydrographs, and tables of daily water levels. Annual measurements of water levels collected during water years 1993-94 from a network of 20 additional, miscellaneous wells are presented. These wells are part of a Statewide network of wells completed in bedrock aquifers that was operated from 1959 through 1989 in cooperation with the Department of Environment and Natural Resources. Site descriptions and hydrographs for the entire period of record for each site also are presented. Drawdown and recovery data are presented for five wells that were pumped (or flowed) for collection of water-quality samples. These wells are part of the network of observation wells for which daily water-level records are compiled. Water-quality data are presented for 20 surface-water sites and 22 ground-water sites. Data presented include field parameters, bacteria counts, and concentrations of common ions, solids, nutrients, trace elements, radiometrics and isotopes, cyanide, phenols, and suspended sediment. Spring data are presented for 94 springs and 21 stream reaches with significant springflow components. Data presented include site information, discharge, and field water-quality parameters including temperature, specific conductance, dissolved oxygen, and pH.

Open-File Report↗