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Mineral Resources Program Office

Mineral Resources Program

John W Powell
12201 Sunrise Valley Drive
Reston , VA 20192-0002
Parent Organization: Office of the Associate Director for Energy, Minerals and Environmental Health
This dataset accompanies the publication, 'In situ LA-ICPMS U-Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to Tertiary', published in Chemical Geology (, which reports a LA-ICPMS analytical procedure for dating cassiterite, a main ore mineral in tin deposits, with no need for an independently dated matrix-matched cassiterite standard.
Ar/Ar data are reported from minerals and rocks that were collected as part of a mineral resource investigation of the Tonopah, Divide, and Goldfield districts in Nevada. Data are reported from 92 samples and associated standards from eight separate neutron irradiations in the Denver USGS TRIGA reactor, including separated mineral grains and whole rocks. Data were collected by infrared laser heating of irradiated samples, either incremental heating or fusion, and analysis by multi-collector mass spectrometry. The reported data have been corrected for blanks, radioactive decay, and interfering nucleogenic reactions associated with sample irradiation.
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...
It has been shown that Environmental Protection Agency (EPA) Method 3060A does not adequately extract Cr(VI) from solids containing chromium ore processing residue (COPR). We systematically modified parameters of EPA 3060A towards improving extraction efficiency of Cr(VI) from the National Institute of Standards and Technology (NIST) standard reference material (SRM) 2701, a standard COPR-contaminated soil from New Jersey, USA. A material similar to NIST 2701 prepared in the laboratory from contaminated soil referred to as 2B was also analyzed. Extraction parameters tested were particle size, glass or polytetrafluoroethylene (PTFE) extraction vessels, volume of extraction solution to mass of sample, and extraction...
We developed and tested a new method for in situ characterization and distribution of inorganic particles in biopsied lung tissue from three diverse human subject groups using field emission scanning electron microscopy with an energy dispersive analyzer. Backscattered electron and secondary electron images of particulate matter in lung tissue were acquired. Inorganic particulate matter in the field of view of the image was analyzed using energy dispersive spectroscopy and subsequently identified and cataloged.
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