Laurel G. Woodruff
Laurel Woodruff is a Scientist Emeritus with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Science and Products
Filter Total Items: 43
History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010 History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010
In 2007, the U.S. Geological Survey, the Geological Survey of Canada, and the Mexican Geological Survey initiated a low-density (1 site per 1600 km2, 13323 sites) geochemical and mineralogical survey of North American soils (North American Soil Geochemical Landscapes Project). Sampling and analytical protocols were developed at a series of workshops in 20032004 and pilot studies were...
Authors
David B. Smith, William F. Cannon, Laurel G. Woodruff, Francisco Moreira Rivera, Andrew N. Rencz, Robert G. Garrett
Pb-concentrations and Pb-isotope ratios in soils collected along an east-west transect across the United States 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...
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 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
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-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...
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 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...
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 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...
Authors
Laurel G. Woodruff, William F. Cannon
Science and Products
Filter Total Items: 43
History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010 History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010
In 2007, the U.S. Geological Survey, the Geological Survey of Canada, and the Mexican Geological Survey initiated a low-density (1 site per 1600 km2, 13323 sites) geochemical and mineralogical survey of North American soils (North American Soil Geochemical Landscapes Project). Sampling and analytical protocols were developed at a series of workshops in 20032004 and pilot studies were...
Authors
David B. Smith, William F. Cannon, Laurel G. Woodruff, Francisco Moreira Rivera, Andrew N. Rencz, Robert G. Garrett
Pb-concentrations and Pb-isotope ratios in soils collected along an east-west transect across the United States 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...
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 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
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-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...
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 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...
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 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...
Authors
Laurel G. Woodruff, William F. Cannon