Geology ReportsSearch

SEARCH · Geology Reports

Results for “Archives of Natural History”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

“Mostri Marini”: Constantine S. Rafinesque's names for three of Antonino Mongitore's Sicilian whales

In 1815, the naturalist Constantine Samuel Rafinesque (1783–1840) previewed three new species of cetaceans – Delphinus dalippus , Physeter urganantus and Oxypterus mongitori – that he intended to describe from Sicily based on illustrations in Antonino Mongitore's published work Della Sicilia ricercata nelle cose più memorabili (1742–1743). Although formal descriptions of the three species were never published, Rafinesque's reference to Mongitore's illustrations made the names available by “indication”. The names, nonetheless, fell into obscurity, most likely a result of contemporary taxonomists' lack of access to Mongitore's work. Rafinesque's names remain relevant to the history of cetacean taxonomy, although they are no longer applicable. Moreover, the animals associated with these names add to the historical record of whale strandings in the Mediterranean. For these reasons, we studied the illustrations Rafinesque indicated for his cetaceans and reviewed Mongitore's accompanying text, which together provide sufficient distinctive characters that two of the three animals can be confidently identified with modern species, namely the sperm whale, Physeter catodon ( Linnaeus, 1758), and the false killer whale, Pseudorca crassidens (Owen, 1846). Had Rafinesque's name D. dalippus been recognized for what it was, it would have had priority over P. crassidens as the earliest scientific name for the false killer whale.

Archives of Natural History

Clarifications and corrections of the dates of issue of some publications containing descriptions of North American birds

The date of issue of a work containing a new scientific name determines the date the name is available and, therefore, the priority of the name with respect to other applied to the same taxon. Differences between the dates printed in publications and the actual dates of issues often resulted from procedures in distribution and erratic publishing schedules, especially before the twentieth century. Distribution, including that to subscribers, was usually the responsibility of the author (Jackson, 1975: 14-15). Early publications were customarily issues in parts (Price, 1982) and the dated title page was usually issued last, which complicates matters of establishing an actual publication date. Early bibliographic works, especially those of Sherborn (e.g., 1902-1933), Mathews (e.g., 1911, 1919, 1925), Waterhouse (e.g., 1885, 1889, 1937), Zimmer (1926), and Richmond (e.g., 1899b, 1902, 1917), have provided information on the actual dates of issue of many ornithological works. Many modern publications (e.g. American Ornithologists' Union [A.O.U.], 1957, 1983; various volumes of Peters's check-lists) have neglected recent, and some older, bibliographic works on several sources of scientific names of birds that affect the proper citations. Here, we clarify information on the dates of issue of some publications on North American ( sensu , A.O.U., 1983) birds. In the event the actual day of issue cannot be determined, the last day of the month or year, whichever was known, or, lacking such information, the printed date, is the date of availability of the scientific name (International Commission on Zoological Nomenclature, 1985: Article 21). Sources for determining the dates of issue include bibliographic works and the invaluable notes of Charles W. Richmond (in the Division of Birds library, Smithsonian Institution). In the following, books are listed alphabetically by the author of the scientific names, and journals by the first word in their title.

Archives of Natural History

Who invented the mule deer ( Odocoileus hemionus )? On the authorship of the fraudulent 1812 journal of Charles Le Raye

The captivity journal of Charles Le Raye was first published in 1812 as a chapter in A topographical description of the state of Ohio, Indiana Territory, and Louisiana , a volume authored anonymously by a late officer in the U. S. Army. Le Raye was purported to be a French Canadian fur trader who, as a captive of the Sioux, had travelled across broad portions of the Missouri and Yellowstone river drainages a few years before the Lewis and Clark expedition (1804-1806), and his account of the land, its people, and its natural resources was relied upon as a primary source by generations of natural historians, geographers, and ethnographers. Based directly on descriptions of animals in the published journal, the naturalist Constantine S. Rafinesque named seven new species of North American mammals, including what are currently recognized as the mule deer ( Odocoileus hemionus ) and a Great Plains subspecies of white-tailed deer ( O. virginianus macrourus ). Unfortunately, Le Raye never existed, and historical, geographical, and ethnographical evidence indicates that the journal is fraudulent. Determining the author of this work is relevant to identifying the sources used to construct it, which may help us to understand the real animals upon which Rafinesque's species are based. Traditionally, authorship of the volume was attributed to Jervis Cutler, but his role in composing the fraudulent Le Raye journal has been called into question. In this paper, I present additional evidence supporting the hypothesis that Jervis Cutler bears primary responsibility for the Le Raye journal and that he had the background, opportunity, and potential motive to author it.

Archives of Natural History

Pranked by Audubon: Constantine S. Rafinesque's description of John James Audubon's imaginary Kentucky mammals

The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. Less well known are a number of “wild rats” described by Rafinesque that include one recognized species ( Musculus leucopus ) and ten other, imaginary “species” fabricated by Audubon ( Gerbillus leonurus , G. megalops , Spalax trivittata , Cricetus fasciatus , Sorex cerulescens , S. melanotis , Musculus nigricans , Lemmus albovittatus , L. talpoides , Sciurus ruber ). Rafinesque's unpublished sketches of these animals provide important insight regarding the supposed nature of the animals invented by Audubon and ultimately published by Rafinesque.

Archives of Natural History

Rafinesque's Sicilian whale, Balena gastrytis

In 1815, the naturalist Constantine S. Rafinesque described a new species of cetacean, Balena gastrytis, from Sicily, based on a whale that stranded on Carini beach near Palermo. In comparing the characteristics of his new whale with known species, Rafinesque also took the opportunity to name a new genus, Cetoptera, to replace Balaenoptera Lacépède, 1804. Unfortunately, few of Rafinesque's contemporaries saw his article, which appeared in Il Portafoglio, a local journal that he published and distributed. The journal remains rare, and awareness of the whale remains minimal, despite its relevance to cetacean taxonomy and understanding of whale diversity and distribution in the Mediterranean. We describe the circumstances of the stranding of the Sicilian whale and provide Rafinesque's original description of the whale, as well as an evaluation of its reported characteristics and its current identity.

Archives of Natural History

The green mole, Astromycter prasinatus T. M. Harris, 1825 (Mammalia: Eulipotyphla: Talpidae): An origin story

Thaddeus William Harris described the green mole of Maine, Condylura prasinata (Mammalia: Eulipotyphla: Talpidae), in the July 1825 issue of the Boston Journal of Philosophy and the Arts , and this was considered the original description of the species throughout most of the nineteenth century. In the early twentieth century, taxonomists began instead to cite an earlier notice in the June 1825 issue of the American Journal of Science and Arts . This short article also described the species, but also established a separate genus for it, Astromycter , despite Harris’s indications elsewhere that the species was congeneric with the star-nosed mole, Condylura cristata (Linnaeus, 1758). Moreover, the American Journal of Science and Arts article cited as its source the “ Machias Star ”, indicating the possibility of an even earlier description of the animal. With Astromycter prasinata in synonymy with C. cristata for over a century, little effort has been exerted to determine whether earlier source materials exist or why, within two months, the green mole was allocated to two different genera by its describer. The question is taxonomically relevant today because C. prasinata predates C. cristata nigra ( Smith, 1940), as an available name for north-eastern populations of star-nosed moles. If subspecies of C. cristata are to be recognized, the north-eastern subspecies should correctly bear the name C. cristata prasinata . In fact, authority for both genus- and species-group names for the green mole have been misattributed since 1825. The descriptions of C. prasinata by Thaddeus William Harris in the Boston Journal of Philosophy and the Arts and American Journal of Science and Arts were preceded by at least three published descriptions of A. prasinatus by Thaddeus Mason Harris, his father.

Archives of Natural History

Microbiomes from biorepositories? 16S rRNA bacterial amplicon sequencing of archived and contemporary intestinal samples of wild mammals (Eulipotyphla: Soricidae)

Interest in gut microbial community composition has exploded recently as a result of the increasing ability to characterize these organisms and a growing understanding of their role in host fitness. New technologies, such as next generation amplicon (16S rRNA) sequencing, have enabled identification of bacterial communities from samples of diverse origin (e.g., fecal, skin, genital, environmental, etc.). Relatively little work, however, has explored the feasibility of utilizing historical samples (e.g., museum archived samples) of varying age, quality, and preservation type. Because natural history collections span multiple decades, these biorepositories have the potential to provide fundamental historical baselines to measure and better understand biodiversity on a changing planet. Utilizing even a small proportion of museum specimens could provide a means of sampling past microbial communities, allowing for direct comparison to contemporary communities and more complete understanding of dynamic shifts through time. We examined the feasibility of obtaining 16S rRNA amplicon microbiome data from whole gastrointestinal tracts (GIs) of shrews of varying age and preservation method, including 5 freshly collected shrew GIs immediately fixed in liquid nitrogen (LN2), 10 ten-year old shrew GIs frozen at −20°C (whole animal), and 10 shrews of varying ages (4 from 1968, 1 from 1980, 1 from 2001, 1 from 2004, 1 from 2007, 1 from 2011 and 2 from 2013) fixed and stored whole in 70% ethanol. Not surprisingly, results of 16S rDNA amplicon sequencing reveal significantly different bacterial communities between different preservation techniques and age of samples. Ten-year old frozen samples had bacterial communities most similar to freshly collected (LN2) samples, while the bacterial communities of both were significantly different from the 70% ethanol preserved samples of various ages. Amongst those preserved in 70% ethanol, age of samples also influenced bacterial community composition. Additionally, we compare results of OTU based and ASV based analyses. Looking ahead, field collectors and museums should develop and adopt best practices related to frozen preservation to ensure adequate material for future microbiome investigations.

Frontiers in Ecology and Evolution

Paleoclimates: Understanding climate change past and present

The field of paleoclimatology relies on physical, chemical, and biological proxies of past climate changes that have been preserved in natural archives such as glacial ice, tree rings, sediments, corals, and speleothems. Paleoclimate archives obtained through field investigations, ocean sediment coring expeditions, ice sheet coring programs, and other projects allow scientists to reconstruct climate change over much of earth's history. When combined with computer model simulations, paleoclimatic reconstructions are used to test hypotheses about the causes of climatic change, such as greenhouse gases, solar variability, earth's orbital variations, and hydrological, oceanic, and tectonic processes. This book is a comprehensive, state-of-the art synthesis of paleoclimate research covering all geological timescales, emphasizing topics that shed light on modern trends in the earth's climate. Thomas M. Cronin discusses recent discoveries about past periods of global warmth, changes in atmospheric greenhouse gas concentrations, abrupt climate and sea-level change, natural temperature variability, and other topics directly relevant to controversies over the causes and impacts of climate change. This text is geared toward advanced undergraduate and graduate students and researchers in geology, geography, biology, glaciology, oceanography, atmospheric sciences, and climate modeling, fields that contribute to paleoclimatology. This volume can also serve as a reference for those requiring a general background on natural climate variability.

Book

Weather and Climate Monitoring Protocol, Channel Islands National Park, California

Weather and climate are strong drivers of population dynamics, plant and animal spatial distributions, community interactions, and ecosystem states. Information on local weather and climate is crucial in interpreting trends and patterns in the natural environment for resource management, research, and visitor enjoyment. This document describes the weather and climate monitoring program at the Channel Islands National Park (fig. 1), initiated in the 1990s. Manual and automated stations, which continue to evolve as technology changes, are being used for this program. The document reviews the history of weather data collection on each of the five Channel Islands National Park islands, presents program administrative structure, and provides an overview of procedures for data collection, archival, retrieval, and reporting. This program overview is accompanied by the 'Channel Islands National Park Remote Automated Weather Station Field Handbook' and the 'Channel Islands National Park Ranger Weather Station Field Handbook'. These Handbooks are maintained separately at the Channel Island National Park as 'live documents' that are updated as needed to provide a current working manual of weather and climate monitoring procedures. They are available on request from the Weather Program Manager (Channel Islands National Park, 1901 Spinnaker Dr., Ventura, CA 93001; 805.658.5700). The two Field Handbooks describe in detail protocols for managing the four remote automated weather stations (RAWS) and the seven manual Ranger Weather Stations on the islands, including standard operating procedures for equipment maintenance and calibration; manufacturer operating manuals; data retrieval and archiving; metada collection and archival; and local, agency, and vendor contracts.

Techniques and Methods

U.S. Geological Survey collections—Preserving the past to inform the future: Tour three federal repositories—Core Research Center, Paleontological Collection, and the NSF National Ice Core Laboratory

This 2016 Geological Society of America (GSA) Annual Meeting trip will explore the Core Research Center, Paleontological Collection, and National Science Foundation National Ice Core Laboratory—three collections of major national signifi cance managed by the U.S. Geological Survey (USGS). Since its inception in 1879, USGS has collected, preserved, and managed physical collections for scientifi c investigations of Earth’s systems. The Core Research Center is the largest federal core repository in the United States, where over 74 million meters (242 million feet) of the subsurface are represented by the collection of rock cores and well cuttings, available for use by researchers investigating resource potential, tectonics, structures, aquifers, and more. The USGS has conducted paleontological research for more than 110 years to inform geological mapping, biostratigraphy, paleoecology, paleoclimate, and other research. Most of these paleontological samples are at the Smithsonian Institution National Museum of Natural History (NMNH) and USGS Denver facilities. The USGS Denver paleontological collection includes ~1.2 million samples. Ancillary materials consisting of handwritten ledgers, index cards, fi eld reports, maps, and other information produced by USGS investigators provide profound knowledge about the specimens and associated geological systems. The USGS is working with NMNH to systematically digitize the collection to preserve and expose samples and data to research. The National Science Foundation (NSF) National Ice Core Laboratory (NICL) is the nation’s repository for preserving, archiving, and sampling meteoric ice cores collected from the world’s ice sheets, ice caps, and glaciers, mostly from Antarctica and Greenland. NICL’s primary mission is to store and curate ice cores, primarily collected during NSF-sponsored projects, for present and future sample investigations.

Colorado

Pennsylvania and Landsat

The Commonwealth of Pennsylvania straddles an array of landscapes. From east to west, its 46,055 square miles connect the sea-level lowlands of the Atlantic seaboard with the rolling hills of the Midwest. It also acts as a bridge between regions from north to south, with the Appalachian Mountains swooping through its center from its northern border with New York to its southern borders with Maryland and West Virginia. The Declaration of Independence and U.S. Constitution were signed in the Commonwealth’s largest city, Philadelphia, and it was the second of the original 13 colonies to ratify the Constitution. The pivotal Civil War battle of Gettysburg took place in the southern part of Pennsylvania. Western Pennsylvania was an early hub for the coal, oil, and steel industries that fueled the Nation’s growth in the 20th century and still factor into Pennsylvania’s economy. The varied natural features of Pennsylvania have been an important proving ground for the value of satellite imagery from the USGS Landsat Program. Scientists began to lean on Landsat observations early in the program’s history to map the effect of invasive moths on Commonwealth forests. That activity continues to this day. Space-based imagery has also contributed to the study and management of land change from energy development, urban growth, and shifting land use patterns. The Landsat Program’s unparalleled 50-year archive of repeat Earth observations remains a critical public resource for Pennsylvania as environmental changes and land use patterns present new challenges to land managers and urban planners in the Keystone State.

Pennsylvania

Assessing the role of climate and resource management on groundwater dependent ecosystem changes in arid environments with the Landsat archive

Groundwater dependent ecosystems (GDEs) rely on near-surface groundwater. These systems are receiving more attention with rising air temperature, prolonged drought, and where groundwater pumping captures natural groundwater discharge for anthropogenic use. Phreatophyte shrublands, meadows, and riparian areas are GDEs that provide critical habitat for many sensitive species, especially in arid and semi-arid environments. While GDEs are vital for ecosystem services and function, their long-term (i.e. ~ 30 years) spatial and temporal variability is poorly understood with respect to local and regional scale climate, groundwater, and rangeland management. In this work, we compute time series of NDVI derived from sensors of the Landsat TM, ETM +, and OLI lineage for assessing GDEs in a variety of land and water management contexts. Changes in vegetation vigor based on climate, groundwater availability, and land management in arid landscapes are detectable with Landsat. However, the effective quantification of these ecosystem changes can be undermined if changes in spectral bandwidths between different Landsat sensors introduce biases in derived vegetation indices, and if climate, and land and water management histories are not well understood. The objective of this work is to 1) use the Landsat 8 under-fly dataset to quantify differences in spectral reflectance and NDVI between Landsat 7 ETM + and Landsat 8 OLI for a range of vegetation communities in arid and semiarid regions of the southwestern United States, and 2) demonstrate the value of 30-year historical vegetation index and climate datasets for assessing GDEs. Specific study areas were chosen to represent a range of GDEs and environmental conditions important for three scenarios: baseline monitoring of vegetation and climate, riparian restoration, and groundwater level changes. Google's Earth Engine cloud computing and environmental monitoring platform is used to rapidly access and analyze the Landsat archive along with downscaled North American Land Data Assimilation System gridded meteorological data, which are used for both atmospheric correction and correlation analysis. Results from the cross-sensor comparison indicate a benefit from the application of a consistent atmospheric correction method, and that NDVI derived from Landsat 7 and 8 are very similar within the study area. Results from continuous Landsat time series analysis clearly illustrate that there are strong correlations between changes in vegetation vigor, precipitation, evaporative demand, depth to groundwater, and riparian restoration. Trends in summer NDVI associated with riparian restoration and groundwater level changes were found to be statistically significant, and interannual summer NDVI was found to be moderately correlated to interannual water-year precipitation for baseline study sites. Results clearly highlight the complementary relationship between water-year PPT, NDVI, and evaporative demand, and are consistent with regional vegetation index and complementary relationship studies. This work is supporting land and water managers for evaluation of GDEs with respect to climate, groundwater, and resource management.

Remote Sensing of Environment

Museum metabarcoding: a novel method revealing gut helminth communities of small mammals across space and time

Natural history collections spanning multiple decades provide fundamental historical baselines to measure and understand changing biodiversity. New technologies such as next generation DNA sequencing (NGS) have considerably increased the potential of museum specimens to address significant questions regarding the impact of environmental changes on host and parasite/pathogen dynamics. We developed a new technique to identify intestinal helminth parasites and applied it to shrews (Eulipotyphla: Soricidae) because they are ubiquitous, occupy diverse habitats, and host a diverse and abundant parasite fauna. Notably, we included museum specimens preserved in various ways to explore the efficacy of using metabarcoding analyses that may enable identification of helminth symbiont communities from historical archives. We successfully sequenced the parasite communities (using 12S mtDNA, 16S mtDNA, 28S rDNA) of 23 whole gastrointestinal (GI) tracts. All GI tracts were obtained from the Museum of Southwestern Biology (MSB), USA, and from recent field collections, varying both in time since fixation (ranging from 4 months to 16 years) and preservation method (70% or 95% ethanol stored at room temperature, or flash frozen in liquid nitrogen and stored at -80°C). Our proof of concept demonstrates the feasibility of applying NGS techniques to authoritatively identify the parasite/pathogen communities within whole GI tracts from museum specimens of varying age and fixation, and the value of future preservation of host-associated whole GI tracts in public research archives. This powerful approach facilitates future comparative examinations of the distributions and interactions among multiple associated groups of organisms through time and space.

International Journal for Parasitology

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

Assessing inundation hazards to nuclear powerplant sites using geologically extended histories of riverine floods, tsunamis, and storm surges

Most nuclear powerplants in the United States are near rivers, large lakes, or oceans. As evident from the Fukushima Daiichi, Japan, disaster of 2011, these water bodies pose inundation threats. Geologic records can extend knowledge of rare hazards from flooding, storm surges, and tsunamis. This knowledge can aid in assessing the safety of critical structures such as dams and energy plants, for which even remotely possible hazards are pertinent. Quantitative analysis of inundation from geologic records perhaps is most developed for and applied to riverine flood hazards, but because of recent natural disasters, geologic investigations also are now used widely for understanding tsunami hazards and coastal storm surges. Layered sedimentary deposits commonly give the most complete geologic record of large floods, storm surges, and tsunamis. Sedimentary layers may be preserved for hundreds or thousands of years in suitable depositional environments, thereby providing an archive of rare, high-magnitude events. All inundation hazards discussed in this report—riverine floods, tsunamis, and storm surges—have had long records extracted from sedimentary sequences, many specifically for hazard assessment. Geologic records commonly are imprecise, so most hazard assessments benefit from evaluation of many sites and rigorous uncertainty assessment. Despite uncertainties, geologic records commonly can improve knowledge of the types and magnitudes of hazards threatening specific sites or regions. New statistical tools and approaches can efficiently incorporate geologic information into frequency assessments. These tools are most developed for riverine flood hazards, but are to some degree transferable to other episodic natural phenomena such as tsunamis and storm surges. Even with these efficient statistical approaches for examining geologic records, systematic landscape changes may reduce the applicability of retrospective assessments. These non-stationarity issues (such as climate change, sea‑level rise, land-use, dams and flow regulation) may all affect the validity of using past experience—no matter how complete the record—to assess future likelihoods. These issues require site-specific consideration for nearly all hazard assessments drawn from geologic evidence. A screening of the 104 nuclear powerplants in the United States licensed by the Nuclear Regulatory Commission (at 64 sites) indicates several sites for which paleoflood studies likely would provide additional flood-frequency information. Two sites—Duane Arnold, Iowa, on the Cedar River; and David-Besse, Ohio, on the Toussaint River—have geologic conditions suitable for creating and preserving stratigraphic records of flooding and few upstream dams that may complicate flood-frequency analysis. One site—Crystal River, Florida1, on the Withlacoochee River and only 4 kilometers from the coast—has high potential as a candidate for assessing riverine and marine inundation hazards. Several sites on the Mississippi River have high geologic potential, but upstream dams almost certainly now regulate peak flows. Nevertheless, studies on the Mississippi River to evaluate long-term flood frequency may provide results applicable to a wide spectrum of regional hazard issues. Several sites in the southeastern United States have high geologic potential, and studies at these sites also may be helpful in evaluating hazards from outburst floods from landslide dams (river blockages formed by mass movements), which may be a regional hazard. For all these sites, closer investigation and field reconnaissance would be needed to confirm suitable deposits and settings for a complete paleoflood analysis. Similar screenings may help identify high-potential sites for geologic investigations of tsunami and storm-surge hazards.

Scientific Investigations Report

History and evaluation of national-scale geochemical data sets for the United States

Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous U.S. The National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance (NURE-HSSR) Program of the U.S. Department of Energy was conducted from 1975 to 1984 and collected either stream sediments, lake sediments, or soils at more than 378,000 sites in both the conterminous U.S. and Alaska. The sampled area represented about 65% of the nation. The Natural Resources Conservation Service (NRCS), from 1978 to 1982, collected samples from multiple soil horizons at sites within the major crop-growing regions of the conterminous U.S. This data set contains analyses of more than 3000 samples. The National Geochemical Survey, a USGS project conducted from 1997 to 2009, used a subset of the NURE-HSSR archival samples as its starting point and then collected primarily stream sediments, with occasional soils, in the parts of the U.S. not covered by the NURE-HSSR Program. This data set contains chemical analyses for more than 70,000 samples. The USGS, in collaboration with the Mexican Geological Survey and the Geological Survey of Canada, initiated soil sampling for the North American Soil Geochemical Landscapes Project in 2007. Sampling of three horizons or depths at more than 4800 sites in the U.S. was completed in 2010, and chemical analyses are currently ongoing. The NRCS initiated a project in the 1990s to analyze the various soil horizons from selected pedons throughout the U.S. This data set currently contains data from more than 1400 sites. This paper (1) discusses each data set in terms of its purpose, sample collection protocols, and analytical methods; and (2) evaluates each data set in terms of its appropriateness as a national-scale geochemical database and its usefulness for national-scale geochemical mapping.

Conterminous United States

Baseline ecological risk assessment of the Calcasieu Estuary, Louisiana: 1. Overview and problem formulation

A remedial investigation/feasibility study (RI/FS) of the Calcasieu Estuary cooperative site was initiated in 1998. This site, which is located in the southwestern portion of Louisiana in the vicinity of Lake Charles, includes the portion of the estuary from the saltwater barrier on the Calcasieu River to Moss Lake. As part of the RI/FS, a baseline ecological risk assessment (BERA) was conducted to assess the risks to aquatic organisms and aquatic-dependent wildlife exposed to environmental contaminants. The purpose of the BERA was to determine if adverse effects on ecological receptors are occurring in the estuary; to evaluate the nature, severity, and areal extent of any such effects; and to identify the substances that are causing or substantially contributing to effects on ecological receptors. This article describes the environmental setting and site history, identifies the chemicals of potential concern, presents the exposure scenarios and conceptual model for the site, and summarizes the assessment and measurement endpoints that were used in the investigation. Two additional articles in this series describe the results of an evaluation of effects-based sediment-quality guidelines as well as an assessment of risks to benthic invertebrates associated with exposure to contaminated sediment.

Louisiana