Laurel G. Woodruff
Laurel Woodruff is a Research Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Science and Products
Filter Total Items: 42
Pb-concentrations and Pb-isotope ratios in soils collected along an east-west transect across the United States
Analytical results for Pb-concentrations and isotopic ratios from ca. 150 samples of soil A horizon and ca. 145 samples of soil C horizon collected along a 4000-km east–west transect across the USA are presented. Lead concentrations along the transect show: (1) generally higher values in the soil A-horizon than the C-horizon (median 21 vs. 16.5 mg/kg), (2) an increase in the median value of the so
Authors
Clemens Reimann, David B. Smith, Laurel G. Woodruff, Belinda Flem
A national-scale geochemical and mineralogical survey of soils of the conterminous United States
In 2007, the US Geological Survey initiated a low-density (1 site per 1600 km2, c. 4800 sites) geochemical and mineralogical survey of soils of the conterminous USA. The ideal sampling protocol at each site includes a sample from 0–5 cm depth, a composite of the soil A horizon, and a sample from the soil C horizon. The <2-mm fraction of each sample is analyzed for Al, Ca, Fe, K, Mg, Na, S, Ti, Ag,
Authors
David B. Smith, William F. Cannon, Laurel G. Woodruff
Magmatic sulfide-rich nickel-copper deposits related to picrite and (or) tholeiitic basalt dike-sill complexes: A preliminary deposit model
Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (±) platinum-group elements (PGEs), account for approximately 60 percent of the world’s Ni production and are active exploration targets in the United States and elsewhere. On the basis of their principal metal production, magmatic sulfide deposits in mafic rocks can be divided into two major types: those that are su
Authors
Klaus J. Schulz, Val W. Chandler, Suzanne W. Nicholson, Nadine M. Piatak, Robert R. Seal, Laurel G. Woodruff, Michael L. Zientek
Environmental baseline study of the Huron River Watershed, Baraga and Marquette Counties, Michigan
This report summarizes results of a study to establish water-quality and geochemical baseline conditions within a small watershed in the Lake Superior region. In 2008, the U.S. Geological Survey (USGS) completed a survey of water-quality parameters and soil and streambed sediment geochemistry of the 83 mi2 Huron River Watershed in the Upper Peninsula of Michigan. Streamflow was measured and water-
Authors
Laurel G. Woodruff, Thomas L. Weaver, William F. Cannon
Immediate and long-term fire effects on total mercury in forests soils of northeastern Minnesota
Within the Boundary Waters Canoe Area Wilderness in northeastern Minnesota, soils were collected from 116 sites in areas of primarily virgin forest with fire-origin stand years (year of last recognizable stand-killing wildfire) that range from the 1759 to 1976. Median concentrations for total mercury in soils for this span of 217 years range from 0.28 ± 0.088 ppm (1759) to 0.09 ± 0.047 ppm (1976)
Authors
Laurel G. Woodruff, William F. Cannon
Total mercury, methylmercury, and selected elements in soils of the Fishing Brook watershed, Hamilton County, New York, and the McTier Creek watershed, Aiken County, South Carolina, 2008
Mercury is an element of on-going concern for human and aquatic health. Mercury sequestered in upland and wetland soils represents a source that may contribute to mercury contamination in sensitive ecosystems. An improved understanding of mercury cycling in stream ecosystems requires identification and quantification of mercury speciation and transport dynamics in upland and wetland soils within a
Authors
Laurel G. Woodruff, William F. Cannon, Christopher D. Knightes, Francis H. Chapelle, Paul M. Bradley, Douglas A. Burns, Mark E. Brigham, Mark A. Lowery
Impact of wildfire on levels of mercury in forested watershed systems: Voyageurs National Park, Minnesota
Atmospheric deposition of mercury to remote lakes in mid-continental and eastern North America has increased approximately threefold since the mid-1800s (Swain and others, 1992; Fitzgerald and others, 1998; Engstrom and others, 2007). As a result, concerns for human and wildlife health related to mercury contamination have become widespread. Despite an apparent recent decline in atmospheric deposi
Authors
Laurel G. Woodruff, Mark B. Sandheinrich, Mark E. Brigham, William F. Cannon
Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield
The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemis
Authors
M.C. Gabriel, R. Kolka, T. Wickman, E. Nater, Laurel G. Woodruff
Preliminary results of the North American Soil Geochemical Landscapes Project, northeast United States and Maritime Provinces of Canada
The results of a soil geochemical survey of the Canadian Maritime provinces and the northeast states of the United States are described. The data presented are for the
Authors
Eric C. Grunsky, David B. Smith, Peter W.B. Friske, Laurel G. Woodruff
Major- and trace-element concentrations in soils from two continental-scale transects of the United States and Canada
This report contains major- and trace-element concentration data for soil samples collected from 265 sites along two continental-scale transects in North America. One of the transects extends from northern Manitoba to the United States-Mexico border near El Paso, Tex. and consists of 105 sites. The other transect approximately follows the 38th parallel from the Pacific coast of the United States n
Authors
David B. Smith, William F. Cannon, Laurel G. Woodruff, Robert G. Garrett, Rodney Klassen, James E. Kilburn, John D. Horton, Harley D. King, Martin B. Goldhaber, Jean Morrison
Geochemistry of bedrock and glacial deposits in the vicinity of the Bend massive sulfide deposit, north central Wisconsin
In 1998 the U.S. Geological Survey (USGS) initiated a study to examine the natural regional environmental impact of sulfide mineralization exposed to episodic weathering and glaciation. The study focused on the Bend copper-gold massive sulfide deposit located in the Medford District of the Chequamegon National Forest in north central Wisconsin. The Bend massive sulfide deposit is a small, metal-ri
Authors
Laurel G. Woodruff, John W. Attig, William F. Cannon, Suzanne W. Nicholson, Klaus Schulz
The geochemical landscape of northwestern Wisconsin and adjacent parts of northern Michigan and Minnesota (geochemical data files)
This data set consists of nine files of geochemical information on various types of surficial deposits in northwestern Wisconsin and immediately adjacent parts of Michigan and Minnesota. The files are presented in two formats: as dbase files in dbaseIV form and Microsoft Excel form. The data present multi-element chemical analyses of soils, stream sediments, and lake sediments. Latitude and longit
Authors
William F. Cannon, Laurel G. Woodruff
Science and Products
Filter Total Items: 42
Pb-concentrations and Pb-isotope ratios in soils collected along an east-west transect across the United States
Analytical results for Pb-concentrations and isotopic ratios from ca. 150 samples of soil A horizon and ca. 145 samples of soil C horizon collected along a 4000-km east–west transect across the USA are presented. Lead concentrations along the transect show: (1) generally higher values in the soil A-horizon than the C-horizon (median 21 vs. 16.5 mg/kg), (2) an increase in the median value of the so
Authors
Clemens Reimann, David B. Smith, Laurel G. Woodruff, Belinda Flem
A national-scale geochemical and mineralogical survey of soils of the conterminous United States
In 2007, the US Geological Survey initiated a low-density (1 site per 1600 km2, c. 4800 sites) geochemical and mineralogical survey of soils of the conterminous USA. The ideal sampling protocol at each site includes a sample from 0–5 cm depth, a composite of the soil A horizon, and a sample from the soil C horizon. The <2-mm fraction of each sample is analyzed for Al, Ca, Fe, K, Mg, Na, S, Ti, Ag,
Authors
David B. Smith, William F. Cannon, Laurel G. Woodruff
Magmatic sulfide-rich nickel-copper deposits related to picrite and (or) tholeiitic basalt dike-sill complexes: A preliminary deposit model
Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (±) platinum-group elements (PGEs), account for approximately 60 percent of the world’s Ni production and are active exploration targets in the United States and elsewhere. On the basis of their principal metal production, magmatic sulfide deposits in mafic rocks can be divided into two major types: those that are su
Authors
Klaus J. Schulz, Val W. Chandler, Suzanne W. Nicholson, Nadine M. Piatak, Robert R. Seal, Laurel G. Woodruff, Michael L. Zientek
Environmental baseline study of the Huron River Watershed, Baraga and Marquette Counties, Michigan
This report summarizes results of a study to establish water-quality and geochemical baseline conditions within a small watershed in the Lake Superior region. In 2008, the U.S. Geological Survey (USGS) completed a survey of water-quality parameters and soil and streambed sediment geochemistry of the 83 mi2 Huron River Watershed in the Upper Peninsula of Michigan. Streamflow was measured and water-
Authors
Laurel G. Woodruff, Thomas L. Weaver, William F. Cannon
Immediate and long-term fire effects on total mercury in forests soils of northeastern Minnesota
Within the Boundary Waters Canoe Area Wilderness in northeastern Minnesota, soils were collected from 116 sites in areas of primarily virgin forest with fire-origin stand years (year of last recognizable stand-killing wildfire) that range from the 1759 to 1976. Median concentrations for total mercury in soils for this span of 217 years range from 0.28 ± 0.088 ppm (1759) to 0.09 ± 0.047 ppm (1976)
Authors
Laurel G. Woodruff, William F. Cannon
Total mercury, methylmercury, and selected elements in soils of the Fishing Brook watershed, Hamilton County, New York, and the McTier Creek watershed, Aiken County, South Carolina, 2008
Mercury is an element of on-going concern for human and aquatic health. Mercury sequestered in upland and wetland soils represents a source that may contribute to mercury contamination in sensitive ecosystems. An improved understanding of mercury cycling in stream ecosystems requires identification and quantification of mercury speciation and transport dynamics in upland and wetland soils within a
Authors
Laurel G. Woodruff, William F. Cannon, Christopher D. Knightes, Francis H. Chapelle, Paul M. Bradley, Douglas A. Burns, Mark E. Brigham, Mark A. Lowery
Impact of wildfire on levels of mercury in forested watershed systems: Voyageurs National Park, Minnesota
Atmospheric deposition of mercury to remote lakes in mid-continental and eastern North America has increased approximately threefold since the mid-1800s (Swain and others, 1992; Fitzgerald and others, 1998; Engstrom and others, 2007). As a result, concerns for human and wildlife health related to mercury contamination have become widespread. Despite an apparent recent decline in atmospheric deposi
Authors
Laurel G. Woodruff, Mark B. Sandheinrich, Mark E. Brigham, William F. Cannon
Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield
The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemis
Authors
M.C. Gabriel, R. Kolka, T. Wickman, E. Nater, Laurel G. Woodruff
Preliminary results of the North American Soil Geochemical Landscapes Project, northeast United States and Maritime Provinces of Canada
The results of a soil geochemical survey of the Canadian Maritime provinces and the northeast states of the United States are described. The data presented are for the
Authors
Eric C. Grunsky, David B. Smith, Peter W.B. Friske, Laurel G. Woodruff
Major- and trace-element concentrations in soils from two continental-scale transects of the United States and Canada
This report contains major- and trace-element concentration data for soil samples collected from 265 sites along two continental-scale transects in North America. One of the transects extends from northern Manitoba to the United States-Mexico border near El Paso, Tex. and consists of 105 sites. The other transect approximately follows the 38th parallel from the Pacific coast of the United States n
Authors
David B. Smith, William F. Cannon, Laurel G. Woodruff, Robert G. Garrett, Rodney Klassen, James E. Kilburn, John D. Horton, Harley D. King, Martin B. Goldhaber, Jean Morrison
Geochemistry of bedrock and glacial deposits in the vicinity of the Bend massive sulfide deposit, north central Wisconsin
In 1998 the U.S. Geological Survey (USGS) initiated a study to examine the natural regional environmental impact of sulfide mineralization exposed to episodic weathering and glaciation. The study focused on the Bend copper-gold massive sulfide deposit located in the Medford District of the Chequamegon National Forest in north central Wisconsin. The Bend massive sulfide deposit is a small, metal-ri
Authors
Laurel G. Woodruff, John W. Attig, William F. Cannon, Suzanne W. Nicholson, Klaus Schulz
The geochemical landscape of northwestern Wisconsin and adjacent parts of northern Michigan and Minnesota (geochemical data files)
This data set consists of nine files of geochemical information on various types of surficial deposits in northwestern Wisconsin and immediately adjacent parts of Michigan and Minnesota. The files are presented in two formats: as dbase files in dbaseIV form and Microsoft Excel form. The data present multi-element chemical analyses of soils, stream sediments, and lake sediments. Latitude and longit
Authors
William F. Cannon, Laurel G. Woodruff