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Shallow subsurface electrical conductivity was mapped at North Root National Wildlife Refuge (NWR) in northeast Montana using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winter of 2017. Data were acquired by towing the DUALEM421 sensor on a sled behind an all-terrain vehicle or snow machine, with the sensor at a nominal height of 0.3 meters (m) above ground surface. Approximately 9 line-kilometers (km) of data were acquired over an area of approximately 1 square-kilometer. Data were manually edited to remove sensor dropouts, lag corrected for apparent offsets between recorded GPS location and data locations for each coil pair, and averaged to a sounding distance of 1m along the survey...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
Montana,
NOROCK,
National Wildlife Refuge, All tags...
North Root,
Northern Rocky Mountain Science Center,
Prairie Pothole Region,
STEPPE,
Science Team about Energy and Plains and Potholes Environments,
Williston Basin,
electromagnetic surveying,
electromagnetics,
environment,
geophysics,
geoscientificInformation,
groundwater,
hydrogeology,
resistivity,
salinity,
water resources, Fewer tags
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This dataset consists of 65 magnetotelluric (MT) stations collected in 2015 near Mountain Pass, California. The U.S. Geological Survey acquired these data to create a regional conductivity model near the Mountain Pass mine. This work is in support of characterizing mineral deposits.
Tags: Apparent Resistivity,
California,
Clark Mountain,
Earth Magnetic Field,
GMEGSC, All tags...
Geology, Minerals, Energy, and Geophysics Science Center,
GeoscientificInformation,
Impedance,
Ivanpah,
MRP,
MT,
Magnetotellurics,
Mescal Ranges,
Mineral Resources Program,
Mojave,
Mountain Pass,
Phase,
San Bernardino County,
Time Series,
Tipper,
electromagnetic surveying,
geophysics,
magnetotelluric surveying, Fewer tags
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This dataset contains chemical and isotopic data from 39 produced water samples collected from sealed separators containing water from horizontal hydrocarbon wells in the lower Eagle Ford Group. The samples were collected from Lavaca and Gonzales counties, Texas in December, 2015. All wells had been in production for longer than 6 months and had produced more than 10,000 barrels (~160,000 liters) of water.
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Temporal and spatial sources of silica for chert remain poorly constrained. Modern sources to the worlds oceans include silica in rivers > aeolian (dust) deposition > sea floor vents and submarine weathering. However, changes in aridity and dust flux during the Phanerozoic may explain variations in the ocean silica cycle and times and places of chert formation. The chemistry of fine quartz dust (FQD) provides a chemical mechanism for the transformation of FQD to polymorphs of silica in chert; FQD is readily dissolved, then reprecipitated as Opal-A by either biotic or abiotic processes. An unequivocal relation between increases in dust flux and biogenic opal-A in the western Pacific Ocean during the past 200 kyr...
Tags: Africa,
Energy Resources,
Geochemistry,
International,
Soil Sciences, All tags...
USGS Science Data Catalog (SDC),
aridity,
chalcedony,
chemistry,
chert,
deposition,
dust,
eolian,
flocculates,
gypsum,
loess,
microcrystalline,
opal,
porcellanite,
quartz,
silica polymorphs,
silt,
wind, Fewer tags
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The table contains oxide and cation compositions of olivine grains from drill core of the Duluth Complex, Minnesota. The oxides were determined by electron probe microanalysis (EPMA) and are reported in weight percent (wt%). The cations were calculated based on the oxide compositions and are reported in mole percent (mol%). Olivine is a magnesium iron orthosilicate mineral with the formula (Mg2+, Fe2+)2SiO4. Olivine forms a solid solution series with magnesium (Mg) at one end and iron (Fe) at the other. Forsterite (Mg2SiO4) is the magnesium endmember and fayalite (Fe2SiO4) is the iron endmember. Minor elements can substitute into the crystal structure, such as manganese (Mn) and nickel (Ni). To better understand...
Categories: Data;
Types: Citation;
Tags: Cook County,
Duluth,
Environmental Health,
Geochemistry,
Lake County, All tags...
Mineralogy,
Minnesota,
St. Louis County,
USGS Science Data Catalog (SDC),
electron microscopy,
mineralogy, Fewer tags
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