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At least 127 records · Page 7Linked to original sources

USGS1990

Geology, geophysics, and geochronology of the Manson impact structure

A problem with the impact hypothesis for the Cretaceous/Tertiary (K/T) mass extinction is the apparent absence of an identifiable impact site. The Manson impact structure is a candidate site because of its size (the largest such structure recognized in the United States); in addition, the largest and most abundant shocked quartz grains at the K/T boundary are found relatively close by, and its age is indistinguishable from that of the K/T boundary. The region of northwest central Iowa that contains the Manson impact structure is covered by Quaternary glacial deposits, which are underlain by Phanerozoic sedimentary rocks (mostly flat-lying carbonates) and Proterozoic red clastic, metamorphic, volcanic, and plutonic rocks. In a circular area about 22 mi (35 km) in diameter around Manson, Iowa, this normal sequence is absent or “disturbed.” Within the structure, three roughly concentric zones of rock associations have been identified: an outer zone of displaced strata, a zone of completely disrupted strata, and a central area in which basement igneous and metamorphic rocks have been uplifted at least 1,220 ft (4,000 m). Gravity, magnetic, and seismic refraction surveys readily identify the central uplift within the structure. Manson is established as an impact structure based on its circular shape, its central uplift, and the presence of shocked quartz within the granitic central uplift. Paleontological evidence, a fission track age, and preliminary 40 Ar/ 39 Ar dating all allowed a K/T boundary age for the Manson structure. Improved 40 Ar/ 39 Ar age spectra may be interpreted in terms of samples that were incompletely degassed during heating due to the Manson impact. An age of 65.7 ± 1.0 Ma was obtained, a value indistinguishable from that of the K/T boundary.

Iowa↗

USGS2021

Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA

Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm −2 year −1 ) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments of pollen deposition processes be quantitatively linked to spatially-explicit measures of plant abundance. Our study addressed these methodological challenges. Modern PAR and vegetation data were obtained from seven lakes in the western Klamath Mountains, California. To determine how to best calibrate our PAR-biomass model, we first calculated the spatial area of vegetation where vegetation composition and patterning is recorded by changes in the pollen signal using two metrics. These metrics were an assemblage-level relevant source area of pollen (aRSAP) derived from extended R-value analysis ( sensu Sugita, 1993) and a taxon-specific relevant source area of pollen (tRSAP) derived from PAR regression ( sensu Jackson, 1990). To the best of our knowledge, aRSAP and tRSAP have not been directly compared. We found that the tRSAP estimated a smaller area for some taxa (e.g. a circular area with a 225 m radius for Pinus ) than the aRSAP (a circular area with a 625 m radius). We fit linear models to relate PAR values from modern lake sediments with empirical, distance-weighted estimates of aboveground live biomass (AGL dw ) for both the aRSAP and tRSAP distances. In both cases, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus , and TCT (Taxodiaceae, Cupressaceae, and Taxaceae families) – were statistically significant and reasonably precise estimators of contemporary AGL dw . However, predictions weighted by the distance defined by aRSAP tended to be more precise. The relative root-mean squared error for the aRSAP biomass estimates was 9% compared to 12% for tRSAP. Our results demonstrate that calibrated PAR-biomass relationships provide a robust method to infer changes in past plant biomass.

California, Oregon↗

USGS2002

Double sampling to estimate density and population trends in birds

We present a method for estimating density of nesting birds based on double sampling. The approach involves surveying a large sample of plots using a rapid method such as uncorrected point counts, variable circular plot counts, or the recently suggested double-observer method. A subsample of those plots is also surveyed using intensive methods to determine actual density. The ratio of the mean count on those plots (using the rapid method) to the mean actual density (as determined by the intensive searches) is used to adjust results from the rapid method. The approach works well when results from the rapid method are highly correlated with actual density. We illustrate the method with three years of shorebird surveys from the tundra in northern Alaska. In the rapid method, surveyors covered ~10 ha h -1 and surveyed each plot a single time. The intensive surveys involved three thorough searches, required ~3 h ha -1 , and took 20% of the study effort. Surveyors using the rapid method detected an average of 79% of birds present. That detection ratio was used to convert the index obtained in the rapid method into an essentially unbiased estimate of density. Trends estimated from several years of data would also be essentially unbiased. Other advantages of double sampling are that (1) the rapid method can be changed as new methods become available, (2) domains can be compared even if detection rates differ, (3) total population size can be estimated, and (4) valuable ancillary information (e.g. nest success) can be obtained on intensive plots with little additional effort. We suggest that double sampling be used to test the assumption that rapid methods, such as variable circular plot and double-observer methods, yield density estimates that are essentially unbiased. The feasibility of implementing double sampling in a range of habitats needs to be evaluated.

The Auk↗

USGS2006

Long-term population monitoring: Lessons learned from an endangered passerine in Hawai‘i

Obtaining reliable population estimates is crucial to monitoring endangered species and developing recovery strategies. The palila ( Loxioides bailleui ) is an endangered seed-eating Hawaiian honeycreeper restricted to the subalpine forests of Mauna Kea, a volcano on the island of Hawai‘i, USA. The species is vulnerable to extinction primarily because >90% of the population is concentrated in <30 km 2 of habitat on the western slope of this high, dormant volcano. Annual surveys of the palila population have been conducted for ecological, legal, and other purposes since 1980. Because refinements to sampling protocols and analytical methods have evolved, we examined means of adapting the monitoring program to produce comparable estimates of abundance over the past 25-year period and into the future. We conducted variable circular plot surveys during the nonbreeding season (Jan–Mar) and this used data to obtain estimates of effective detection radius and annual density with Distance 4.0, Release 2. For comparability over the time-series, we excluded from analysis the data from new transects. We partitioned the 25-year data set (1980–1996 and 1997–2004) into 2 separate analyses because, beginning in 1997, observers received more training to reduce their tendency to estimate distances to 5-m intervals. We used geographic strata in the analysis of recent surveys because changes in habitat may have invalidated the density-based strata used previously. By adding observer and year and observer and time of day as co-variables, we improved the model fit to the 2 data sets, respectively. Annual estimates were confounded by changes in sampling methodology and analytical procedures over time. However, the addition of new transects, increased training for observers, and use of exact distance estimates instead of rounding also improved model fit. Habitat characteristics and behavior of palila that potentially influenced detection probability, sampling, analysis, and interpretation were regeneration of trees in response to reduced numbers of introduced browsing mammals, seasonally variable rates of vocalization, non-territoriality, and resource-tracking along an elevation gradient. We believe our adaptive approach to analysis and interpretation of 25 years of annual variable circular plot data could help guide similar long-term monitoring efforts.

Hawai'i↗

USGS2002

Influences of herbivory and water on willow in elk winter range

Elimination of large predators and reduced hunter harvest have led to concerns that an increasing elk ( Cervus elaphus ) population may be adversely affecting vegetation on the low-elevation elk winter range of Rocky Mountain National Park, Colorado, USA. Beaver ( Castor canadensis ) and their impoundments also have declined dramatically (94%) in the same area over the past 50 years coincident with a 20% decline in willow ( Salix spp.) cover. From 1994 to 1998, we studied vegetation production responses of willow communities to elk herbivory and water availability. We estimated willow production by measuring current annual growth of shrubs in 9.3-m2 circular plots, and we measured herbaceous production by clipping vegetation within 0.25-m2 circular plots. Elk herbivory suppressed willow heights, leader lengths, annual production, and herbaceous productivity of willow communities. Water impoundment had a positive effect on herbaceous plant production, but little effect on shrubs, possibly because water tables were naturally high on the study sites even without beaver dams. Nevertheless, the winter range environment previously included more riparian willow habitat because of more stream area (47-69%) due to larger beaver populations. Elk herbivory appears to be the dominant force determining vegetation productivity in willow sites, but the effects may be exacerbated by lowered water tables. Fewer elk or protection from browsing, and water enhancement for <10 years along with management to encourage elk movement away from willow communities, could possibly work as strategies to reestablish sustainable willow communities.

Colorado↗

USGS2015

Minerals, lands, and geology for the common defence and general welfare, Volume 4, 1939-1961: A history of geology in relation to the development of public-land, federal science, and mapping policies and the development of mineral resources in the United States from the 60th to the 82d year of the U.S. Geological Survey

The fourth volume of the comprehensive history of the U.S. Geological Survey (USGS) is titled “Minerals, Lands, and Geology for the Common Defence and General Welfare—Volume 4, 1939‒1961.” The title is based on a passage in the preamble of the U.S. Constitution. The late Mary C. Rabbitt (1915‒2002), a geophysicist who served with the U.S. Coast and Geodetic Survey (1948‒1949) and the USGS (1949‒1978), wrote the first three volumes in this series of USGS Special Books. “Volume 1, Before 1879” (1979), “Volume 2, 1879‒1904” (1980), and “Volume 3, 1904‒1939” (1986), although long out of print and out of stock, are now available online; see links at right. The 704-page Volume 4, supplemented by more than 200 illustrations, was begun by Rabbitt and completed by coauthor Clifford M. Nelson, a geologist with the USGS since 1976. The book is described as “A History of Geology in Relation to the Development of Public-Land, Federal Science, and Mapping Policies and the Development of Mineral Resources in the United States From the 60th to the 82d Year of the U.S. Geological Survey.” Volume 4 focuses on the United States and the USGS in war and peace from the beginning of World War II in Europe to the end of the administration of President Dwight D. Eisenhower. Like the earlier books in the series, Volume 4 places the nature and significance of USGS operations in mapping and the earth sciences in the wider contexts of national and international history. The new volume, like its three predecessors, is intended for general readers and historians alike, so it follows a chronological rather than a thematic pattern, although themes are traced throughout the book. After preparing Volumes 1–3, Rabbitt wrote a brief report summarizing the agency's history in its first century, “The United States Geological Survey: 1879‒1989,” which was originally issued as USGS Circular 1050 in 1989. It was reissued in 2000 as part of USGS Circular 1179, which also contains Renée M. Jaussaud’s inventory of documents accessioned through 1997 into Record Group 57 (USGS) at the National Archives and Records Administration’s Archives II facility (NARA II) in College Park, Maryland.

Book↗

USGS2013

U.S. Geological Survey Water Science Strategy

This fact sheet describes the Water Science Strategy, presented in detail in Circular 1383-G, "U.S. Geological Survey Water Science Strategy--Observing, Understanding, Predicting, and Delivering Water Science to the Nation." This fact sheet looks at the relevant issues facing society and describes the strategy built around observing, understanding, predicting, and delivering water science for the next 5 to 10 years by building new capabilities, tools, and delivery systems to meet the Nation’s water-resource needs. This fact sheet presents the vision of water science for the U.S. Geological Survey and the societal issues that are influenced by, and in turn influence, the water resources of the Nation. The fact sheet describes the five goals of the Water Science Strategy. Nine priority actions also are presented, which combine and elevate the numerous specific strategic actions contained within Circular 1383-G. The fact sheet concludes with a discussion of the intended outcomes of the Water Science Strategy.

Fact Sheet↗

USGS2017

Cooperative Fish and Wildlife Research Units Program—2016 year in review postcard

Cooperative Fish and Wildlife Research Units Program—2016 Year in Review postcard This postcard provides details about the Cooperative Fish and Wildlife Research Units (CRU) Program—2016 Year in Review, Circular 1424. This Circular provides information relating to fish and wildlife science, students, staffing, vacancies, research funding, outreach and training, science themes, background on the CRU program, accolades, and professional services. Snapshots of Unit projects with information on how results have been or are being applied by cooperators are included. This is the essence of what we do: science that matters. Throughout the year, keep up with our research projects at www.coopunits.org .

General Information Product↗

USGS2002

Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska

Kanaga Volcano is a steep-sided, symmetrical, cone-shaped, 1307 meter high, andesitic stratovolcano on the north end of Kanaga Island (51°55’ N latitude, 177°10’ W longitude) in the western Aleutian Islands of Alaska. Kanaga Island is an elongated, low-relief (except for the volcano) island, located about 35 kilometers west of the community of Adak on Adak Island and is part of the Andreanof Islands Group of islands. Kanaga Volcano is one of the 41 historically active volcanoes in Alaska and has erupted numerous times in the past 11,000 years, including at least 10 eruptions in the past 250 years (Miller and others, 1998). The most recent eruption occurred in 1993-95 and caused minor ash fall on Adak Island and produced blocky aa lava flows that reached the sea on the northwest and west sides of the volcano (Neal and others, 1995). The summit of the volcano is characterized by a small, circular crater about 200 meters in diameter and 50-70 meters deep. Several active fumaroles are present in the crater and around the crater rim. The flanking slopes of the volcano are steep (20-30 degrees) and consist mainly of blocky, linear to spoonshaped lava flows that formed during eruptions of late Holocene age (about the past 3,000 years). The modern cone sits within a circular caldera structure that formed by large-scale collapse of a preexisting volcano. Evidence for eruptions of this preexisting volcano mainly consists of lava flows exposed along Kanaton Ridge, indicating that this former volcanic center was predominantly effusive in character. In winter (October-April), Kanaga Volcano may be covered by substantial amounts of snow that would be a source of water for lahars (volcanic mudflows). In summer, much of the snowpack melts, leaving only a patchy distribution of snow on the volcano. Glacier ice is not present on the volcano or on other parts of Kanaga Island. Kanaga Island is uninhabited and is part of the Alaska Maritime National Wildlife Refuge, managed by the U.S. Fish and Wildlife Service. The island is remote and often shrouded by clouds and fog. It can be reached only by boat, helicopter,or amphibiouslanding aircraft.

Alaska↗

USGS2005

Developing ecological criteria for prescribed fire in South Florida pine rockland ecosystems

The pine rocklands of South Florida, characterized by a rich herbaceous flora with many narrowly endemic taxa beneath an overstory of south Florida slash pine (Pinus elliottii var. densa), are found in three areas: the Miami Rock Ridge of southeastern peninsular Florida, the Lower Florida Keys, and slightly elevated portions of the southern Big Cypress National Preserve. Fire is an important element in these ecosystems, since in its absence the pine canopy is likely to be replaced by dense hardwoods, resulting in loss of the characteristic pineland herb flora. Prescribed fire has been used in Florida Keys pine forests since the creation of the National Key Deer Refuge (NKDR), with the primary aim of reducing fuels. Because fire can also be an effective tool in shaping ecological communities, we conducted a 4-year research study which explored a range of fire management options in NKDR. The intent of the study was to provide the Fish and Wildlife Service and other land managers with information regarding when and where to burn in order to perpetuate these unique forests. In 1998 we initiated a burning experiment in a randomized complete block design. Three treatments were to be carried out in a single well-defined block in each of two characteristic understory types during each year from 1998 through 2000. One understory type was characterized by a relatively sparse shrub layer and a well-developed herb layer ('open'), and the second had a dense shrub layer and poorly developed herb layer ('shrubby'). The three burn treatments were: (a) summer burn, (b) winter burn, and (c) no burn, or control. Three 1- ha plots were established in each block, and randomly assigned to the three treatments. Though the first year experimental burns were carried out without incident, constraints posed by external factors, including nationwide and statewide prohibitions on prescribed burning due to wildfires in other regions, delayed the experimental burns and precluded collection of postburn data on one third of the burns. Ultimately we burned only eleven plots, three in winter and eight in summer, over a four-year period from 1998 to 2001. Vegetation was sampled in a stratified, nested design within 18 plots. Trees were sampled in a 1.0-ha plot, shrubs in twenty 50-m2 circular (radius 4 m) subplots within the tree plot, and the herb layer in four circular 1-m2 quadrats (radius 0.57 m) within each subplot. The amount of fuel in the shrub layer was estimated by applying regression models to plant dimensional data, and ground layer fuel was estimated by a harvest method. The effects of Key deer herbivory on regeneration of the understory pine rockland plant community after fire was studied by monitoring inside and outside exclosures established within two of the six blocks. Pine trees constituted more than half (53.3%) of the biomass, but understory fine fuels comprised a surprisingly high proportion of total aboveground biomass. In the three blocks in which paired summer and winter burns were successfully conducted, the summer burns were more intense than the winter burns as judged by our indicators of fire intensity. Because of the differences in fire intensity between seasons, it was not possible to say whether observed differences in vegetation response between summer and winter burns were due to season or to fire intensity. The mortality of South Florida slash pine trees was greater after the summer burn than the winter burn in each block, but other vegetation responses were rarely as consistent. For instance, Metopium showed less recovery after summer burns in two blocks and after the winter burn in the third block. Moreover, there were instances in which alternative growth stages of the same species responded differently. Adult palms succumbed more frequently to summer than winter burns, and mortality of Coccothrinax exceeded that of Thrinax. In contrast, small palms recovered more readily after summer burns than winter burns. High in

Florida↗

USGS2008

Instrumentation Guidelines for the Advanced National Seismic System

This document provides guidelines for the seismic-monitoring instrumentation used by long-term earthquake-monitoring stations that will sense ground motion, digitize and store the resulting signals in a local data acquisition unit, and optionally transmit these digital data. These guidelines are derived from specifications and requirements for data needed to address the nation's emergency response, engineering, and scientific needs as identified in U.S. Geological Survey Circular 1188 (1999). Data needs are discussed in terms of national, regional, and urban scales of monitoring in section 3. Functional performance specifications for instrumentation are introduced in section 4.3 and discussed in detail in section 6 in terms of instrument classes and definitions described in section 5. System aspects and testing recommendations are discussed in sections 7 and 8, respectively. Although U.S. Geological Survey Circular 1188 (1999) recommends that the Advanced National Seismic System (ANSS) include portable instrumentation, performance specifications for this element are not specifically addressed in this document. Nevertheless, these guidelines are largely applicable to portable instrumentation. Volcano monitoring instrumentation is also beyond the scope of this document. Guidance for ANSS structural-response monitoring is discussed briefly herein but details are deferred to the ANSS document by the ANSS Structural Response Monitoring Committee (U.S. Geological Survey, 2005). Aspects of station planning, siting, and installation other than instrumentation are beyond the scope of this document.

Open-File Report↗

USGS2023

System characterization report on the BlackSky Global multispectral sensor

Executive Summary This report addresses system characterization of the BlackSky Global satellites and is part of a series of system characterization reports produced and delivered by the U.S. Geological Survey Earth Resources Observation and Science Cal/Val Center of Excellence. These reports present and detail the methodology and procedures for characterization; present technical and operational information about the specific sensing system being evaluated; and provide a summary of test measurements, data retention practices, data analysis results, and conclusions. The BlackSky Global satellites are three-band multispectral imagers (red, green, and blue multispectral bands plus a panchromatic band) with a 0.8- to 0.9-meter (m) pixel ground sample distance for the assessed satellites. BlackSky Global satellites 9 and 12–17 were launched in March and December 2021, respectively, into a Sun-synchronous orbit of 430–450 kilometers with an inclination of 42–53 degrees and a swath width of 6 kilometers at nadir. Each Global satellite has an expected lifetime of about 3 years. More information on the BlackSky Global satellites is available in the “Land Remote Sensing Satellites Online Compendium” ( https://calval.cr.usgs.gov/apps/compendium ) and from BlackSky at Real-Time Space-Based Intelligence (blacksky.com) The Earth Resources Observation and Science Cal/Val Center of Excellence system characterization team completed data analyses to characterize the geometric (interior and exterior) and spatial performances. Results of these analyses indicate that the assessed BlackSky Global satellites have an interior geometric performance in the range of −0.011 m (−0.012 pixel) to 0.007 m (0.008 pixel) in easting and −0.018 m (−0.020 pixel) to 0.012 m (0.013 pixel) in northing in band-to-band registration; an exterior geometric performance using ground control points of 8.0-m circular error (95-percent certainty) for orthorectified products and 10.7- to 17.4-m circular error (95-percent certainty) for nonorthorectified products, depending on the geolocation metadata used; and a spatial performance in the range of 1.70 to 2.43 pixels for full width at half maximum, with a modulation transfer function at a Nyquist frequency in the range of 0.032 to 0.084.

Open-File Report↗

USGS2025

Insights and strategic opportunities from the USGS 2024 Per- and Polyfluoroalkyl Substances (PFAS) Interagency Workshop

Introduction In 2021, the U.S. Geological Survey (USGS) published Circular 1490 titled, “Integrated Science for the Study of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) in the Environment: A Strategic Science Vision for the U.S. Geological Survey” (Tokranov and others, 2021). Circular 1490 was created to be a resource for USGS scientists prioritizing and planning research related to per- and polyfluoroalkyl substances (PFAS) and to be a guide for developing partnerships with other scientists, State and Federal agencies, and stakeholders engaged in PFAS research and management and mitigation of the environmental and human-health effects of PFAS. This USGS PFAS Strategic Science Vision document was intended to be the foundation for a “living strategic vision,” periodically providing updates on the state of USGS PFAS research, emerging PFAS data gaps and needs, and progress on interagency and stakeholder PFAS partnerships and priorities. To meet this objective, the USGS planned to host an Interagency and Stakeholder PFAS Workshop every 2–3 years. During September 10–12, 2024, the USGS hosted the first Interagency and Stakeholder PFAS Workshop in Reston, Virginia. The Workshop brought together experts from other Federal agencies (U.S. Environmental Protection Agency, National Institute of Environmental Health Sciences, Food and Drug Administration, Department of Defense [Air Force, Army]), State agencies (Washington Fish and Wildlife, Virginia Department of Transportation), and academia (Harvard University, University of Maryland) to address key challenges relating to the measurement and modeling of PFAS and the implications for environmental health. Participants engaged in in-depth discussions centered around six pivotal topics related to PFAS: (1) sampling protocols, methods and interpretation; (2) environmental sources, source apportionment, and occurrence; (3) environmental fate and transport; (4) human and wildlife exposure routes and risk; (5) bioconcentration, bioaccumulation, and biomagnification; and (6) ecotoxicology and effects. Each topic had three breakout sessions. A recurrent theme of workshop discussions was how data on a nationwide scale for PFAS occurrence in various environmental matrices, including air, water, food crops, biota, soil, and streambed sediment could help to advance scientific understanding. Participants noted significant geospatial data gaps, particularly in the midwestern and southern United States and the Pacific Northwest. PFAS data collection tends to be more robust along the eastern seaboard and in California. Participants stressed how enhancing the integration of large and small datasets across various agencies could help to support national scale understanding of PFAS. To address these gaps, attendees suggested leveraging datasets from Federal entities like the USGS and the U.S. Department of Defense, State agencies, and municipal utility services to develop predictive contaminant detection and transport models. Improved coordination between water quality programs and USGS research could help to facilitate access to valuable data, leading to comprehensive databases that inform PFAS point (wastewater treatment plants and landfills) and nonpoint (runoff from land, atmospheric deposition, food packaging) sources, environmental transport mechanisms, environmental detection and concentrations, potential exposure routes, and health effects on different biota, including humans. A specific request was made to develop a map demarking the depth of modern (1953 or later) groundwater, which is susceptible to surface-derived anthropogenic (that is, human-made) contamination, based on tritium-age dating. Emphasis was placed on incorporation of hydrology, groundwater flow paths, groundwater–surface water interactions, and landscape factors in predictive statistical models as a step to improve contaminant source identification and tracking. Molecular fingerprinting approaches garnered attention as techniques to link specific PFAS mixtures detected in a sample to environmental sources and levels in biota (Dávila-Santiago and others, 2022). Integrating data from abiotic (that is, water, soil, and air) and biotic (that is, living organisms) systems identified as a research opportunity. For example, understanding the composition of soils and sediments, which include a mixture of mineral, plant, and animal components, could advance understanding of exposure pathways. The discussions highlighted opportunities to explore and understand the potential redistribution and biotic exposures of PFAS from biosolid and wastewater treatment plant effluent land application practices, in addition to atmospheric releases and discharges from landfill and wastewater treatment plants. Participants identified research gaps surrounding how these sources may contribute to contamination and may affect surrounding ecosystems, including a better definition of anthropogenic background concentrations. Moving forward, the collection of co-occurrence data was noted as a means to improve understanding of complex mixtures and to leverage companion modeling efforts focused on areas with high and low contamination levels to identify areas of concern and unaffected resources. Participants emphasized how centralized USGS databases and the establishment of sample-metadata archives can help to ensure that samples are preserved and accessible for future research. In conclusion, the workshop participants identified opportunities to bridge data gaps and improve measurement techniques, modeling frameworks, databases, and communication, to enhance the understanding of PFAS and their effects on environmental and human health. Upon completion of the workshop, participants indicated an interest in developing strategic data collection, modeling, and analytical approaches to address these challenges.

Open-File Report↗

USGS1951

Stratigraphic sections of the Phosphoria formation in Idaho

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will be released as Circulars within the next few months. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication, the tabular data to be included in these Circulars are hereby placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that immediate use may be made of the data. The tables include data on sections in four states: Montana, Idaho, Wyoming, and Utah; and the tables for each of these states are bound together as individual reports. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data on the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 0 3 , Fe 7 0 3 , loss on ignition, F, and V 2 O 5 , for selected samples. Spectrographic analyses for a large number of elements are included samples from selected localities, and special analyses have been made of a few samples. These reports are placed on open file at the offices of the Geological Survey in Washington, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, and the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Idaho↗

USGS1951

Stratigraphic sections of the Phosphoria formation in Montana

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will be released as Circulars within the next few months. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication, the tabular data to be included in these Circulars are hereby placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that immediate use may be made of the data. The tables include data on sections in four states: Montana, Idaho, Wyoming, and Utah; and the tables for each of these states are bound together as individual reports. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data on the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 0 3 , Fe 7 0 3 , loss on ignition, F, and V 2 O 5 , for selected samples. Spectrographic analyses for a large number of elements are included samples from selected localities, and special analyses have been made of a few samples. The work in Montana has been done with the aid of Missouri River Basin funds as part of a Program of appraisal of the Missouri Basin mineral resources. These reports are placed on open file at the offices of the Geological Survey in Washington, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Montana↗

USGS1951

Stratigraphic sections of the Phosphoria formation in Utah

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will be released as Circulars within the next few months. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication: the tabular data to be included in these Circulars are hereby placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that immediate use may be made of the data. The tables include data on sections in four states: Montana, Idaho, Wyoming, and Utah; and the tables for each of these states are bound together as individual reports. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data or the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 0 3 , Fe 7 0 3 , loss on ignition, F, and V 2 O 5 , for selected samples. Spectrographic analyses for a large number of elements are included for samples from selected localities, and special analyses have been made of a few samples. These reports are placed on open file at the offices of the Geological Survey in Washington, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, and the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Utah↗

USGS1951

Stratigraphic sections of the Phosphoria formation in Wyoming

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will be released as Circulars within the next few months. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication, the tabular data to be included in these Circulars are hereby placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that immediate use may be made of the data. The tables include data on sections in four states: Montana, Idaho, Wyoming, and Utah; and the tables for each of these states are bound together as individual reports. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data on the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 0 3 , Fe 7 0 3 , loss on ignition, F, and V 2 O 5 , for selected samples. Spectrographic analyses for a large number of elements are included 2 5, for samples from selected localities, and special analyses have been made of a few samples. These reports are placed on open file at the offices of the Geological Survey in Washington, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, and the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Wyoming↗

USGS1952

Stratigraphic sections of the Phosphoria formation in Idaho (third Idaho report)

The first of a series of reports giving detailed stratigraphic sections of the Phosphoria formation in the Western phosphate field as measured and described by the Geological Survey will soon be published as Circulars. Because of the needs of industry for many of these data during the 1951 field season, and in view of the unavoidable delays attendant on publication, the tabular data to be included in five of these Circulars have already been placed on open file in simple reproduction form (prepared by Ozalid from photographic negatives) and without explanatory text so that early use could be made of the data. The first four sets of tables, one each for the states of Montana, Idaho, Wyoming, and Utah, were released on open file on August 15, 1951, A second Idaho report was released on October 4, 1951. This report includes data of the same character but of samples from different localities and is the third report on samples from Idaho. The tables include name and location of section measured, brief description of geologic setting, acknowledgments for field and analytical work, abstract data on the sections (bed number, rock name, sample number, and thickness), and analytical data on the samples. The analytical data include reports on P 2 O 5 and acid insoluble for all samples and additional analyses, such as Al 2 O 3 , Fe 2 O 3 , and loss on ignition for selected samples. These reports are placed on open file at the offices of the Geological Survey in Washinton, D. C., Spokane, Washington, Salt Lake City, Utah, and Montpelier, Idaho, and at the offices of the Idaho Bureau of Mines and Geology, Moscow, Idaho, the Montana Bureau of Mines and Geology, Butte, Montana, the Wyoming Geological Survey, Laramie, Wyoming, and the University of Utah, Salt Lake City, Utah.

Idaho↗