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Stephen A Wilson (Former Employee)

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Geochemical and mineralogical properties of Boquillas Shale geochemical reference material ShBOQ-1

The ShBOQ-1 geochemical reference material is relevant to studies of the organic geochemistry and mineralogy of petroleum source rocks containing high concentrations of carbonate minerals and organic sulfur-rich, oil-prone marine organic matter. ShBOQ-1 is geochemically and mineralogically similar to the lower part of the Upper Cretaceous Eagle Ford Shale.
Authors
Justin E. Birdwell, Stephen A. Wilson
By
Energy Resources Program, Mineral Resources Program, Central Energy Resources Science Center, Geology, Geophysics, and Geochemistry Science Center

Variability in results from mineralogical and organic geochemical interlaboratory testing of U. S. Geological Survey shale reference materials

The expansion of unconventional petroleum resource exploration and production in the United States has led to an increase in source rock characterization efforts, particularly related to bulk organic and mineralogical properties. To support the analytical and research needs of industry and academia, as well as internal work, the U.S. Geological Survey (USGS) has collected and prepared shale geoche
Authors
Justin E. Birdwell, Stephen A. Wilson
By
Energy Resources Program, Geology, Geophysics, and Geochemistry Science Center, Central Energy Resources Science Center

High microscale variability in Raman thermal maturity estimates from shale organic matter

Raman spectroscopy has recently received attention as a means to estimate thermal maturity of organic matter in petroleum generating source rocks to complement more traditional approaches such as vitrinite reflectance and programmed pyrolysis. While many studies have observed positive correlations between source rock thermal maturity and Raman spectral parameters, little attention has been given t
Authors
Aaron M. Jubb, Palma J. Botterell, Justin E. Birdwell, Robert C. Burruss, Paul C. Hackley, Brett J. Valentine, Javin J. Hatcherian, Stephen A. Wilson
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Energy Resources Program, Geology, Energy & Minerals Science Center

Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale crater, Mars

The landforms of northern Gale crater on Mars expose thick sequences of sedimentary rocks. Based on images obtained by the Curiosity rover, we interpret these outcrops as evidence for past fluvial, deltaic, and lacustrine environments. Degradation of the crater wall and rim probably supplied these sediments, which advanced inward from the wall, infilling both the crater and an internal lake basin
Authors
J.P. Grotzinger, S. Gupta, M. C. Malin, D. M. Rubin, J. Schieber, K. Siebach, D.Y. Sumner, K.M. Stack, A.R. Vasavada, R.E. Arvidson, F. Calef, Lauren A. Edgar, W. F. Fischer, J.A. Grant, J.L. Griffes, L.C. Kah, M.P. Lamb, K.W. Lewis, N. Mangold, M.E. Minitti, M.C. Palucis, M. Rice, R.M.E. Williams, R.A. Yingst, D. Blake, D. Blaney, P. Conrad, J.A. Crisp, W. E. Dietrich, G. Dromart, K.S. Edgett, R.C. Ewing, R. Gellert, J.A. Hurowitz, G. Kocurek, P.G. Mahaffy, M.J. McBride, S. M. McLennan, M.A. Mischna, D. Ming, R.E. Milliken, H. Newsom, D. Oehler, T. J. Parker, D. Vaniman, R. C. Wiens, S. A. Wilson
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Natural Hazards Mission Area, Astrogeology Science Center

Preparation and characterization of "Libby Amphibole" toxicological testing material

The U.S. Environmental Protection Agency (USEPA) began work in Libby, Mont. in 1999 when an Emergency Response Team was sent to investigate local concern and media reports regarding asbestos-contaminated vermiculite. Since that time, the site has been granted Superfund status and site remediation to a safe level of asbestos has been ongoing. The amphibole asbestos from the Vermiculite Mountain ver
Authors
Heather Lowers, Stephen A. Wilson, Todd M. Hoefen, William Benzel, Gregory P. Meeker
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory, Spectroscopy Lab

GSD-1G and MPI-DING Reference Glasses for In Situ and Bulk Isotopic Determination

This paper contains the results of an extensive isotopic study of United States Geological Survey GSD-1G and MPI-DING reference glasses. Thirteen different laboratories were involved using high-precision bulk (TIMS, MC-ICP-MS) and microanalytical (LA-MC-ICP-MS, LA-ICP-MS) techniques. Detailed studies were performed to demonstrate the large-scale and small-scale homogeneity of the reference glasses
Authors
K.P. Jochum, S. A. Wilson, W. Abouchami, M. Amini, J. Chmeleff, A. Eisenhauer, E. Hegner, L.M. Iaccheri, B. Kieffer, J. Krause, W.F. McDonough, R. Mertz-Kraus, I. Raczek, R.L. Rudnick, Donna K. Scholz, G. Steinhoefel, B. Stoll, A. Stracke, S. Tonarini, D. Weis, U. Weis, J.D. Woodhead

Evaluation of extraction methods for hexavalent chromium determination in dusts, ashes, and soils

One of the difficulties in performing speciation analyses on solid samples is finding a suitable extraction method. Traditional methods for extraction of hexavalent chromium, Cr(VI), in soils, such as SW846 Method 3060A, can be tedious and are not always compatible with some determination methods. For example, the phosphate and high levels of carbonate and magnesium present in the U.S. Environment
Authors
Ruth E. Wolf, Stephen A. Wilson
By
Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center

Development of a standard reference material for Cr(vi) in contaminated soil

Over the last several decades, considerable contamination by hexavalent chromium has resulted from the land disposal of Chromite Ore Processing Residue (COPR). COPR contains a number of hexavalent chromium-bearing compounds that were produced in high temperature industrial processes. Concern over the carcinogenic potential of this chromium species, and its environmental mobility, has resulted in e
Authors
S.J. Nagourney, S. A. Wilson, B. Buckley, H.M.S. Kingston, S.-Y. Yang, S.E. Long

Development of lunar regolith simulant: From the macro to the micro

[No abstract available]
Authors
H.A. Lowers, D. B. Stoeser, S. A. Wilson, G.P. Meeker

USGS Reference Materials Program: Serving the Needs of the Global Analytical Community

Every year in the United States, millions of measurements are made on the chemical composition of items that affect us on a daily basis. The accuracy of these measurements is routinely determined by the analysis of appropriate reference materials. In the field of earth science, reference materials are particularly important because they help us develop a better understanding of the processes that
Authors
Ruth E. Wolf, Stephen A. Wilson

Silurian extension in the Upper Connecticut Valley, United States and the origin of middle Paleozoic basins in the Québec embayment

Pre-Silurian strata of the Bronson Hill arch (BHA) in the Upper Connecticut Valley, NH-VT are host to the latest Ludlow Comerford Intrusive Suite consisting, east to west, of a mafic dike swarm with sheeted dikes, and an intrusive complex. The rocks are mostly mafic but with compositions ranging from gabbro to leucocratic tonalite. The suite is truncated on the west by the Monroe fault, a late Aca
Authors
D.W. Rankin, R.A. Coish, R. D. Tucker, Z.X. Peng, S. A. Wilson, A.A. Rouff

Development and certification of the new SRM 695 trace elements in multi-nutrient fertilizer

During the past seven years, several states within the US have enacted regulations that limit the amounts of selected non-nutritive elements in fertilizers. Internationally, several countries, including Japan, China, and Australia, and the European Union also limit the amount of selected elements in fertilizers. The elements of interest include As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn. Ferti
Authors
E.A. MacKey, M.P. Cronise, C.N. Fales, R.R. Greenberg, S.D. Leigh, S.E. Long, A.F. Marlow, K.E. Murphy, R. Oflaz, J.R. Sieber, M.S. Rearick, L.J. Wood, L.L. Yu, S. A. Wilson, Paul H. Briggs, Z. A. Brown, J. Budahn, P.F. Kane, W.L. Hall
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reference materials

Development of USGS Geochemical Reference Materials

The project focus was the development of traditional and microanalytical reference materials that support USGS geochemical investigations. Development of new microanalytical reference materials allows USGS scientists and outside customers to examine a greater range of sample types while maintaining a high degree of data reliability.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
link

Development of USGS Geochemical Reference Materials

The project focus was the development of traditional and microanalytical reference materials that support USGS geochemical investigations. Development of new microanalytical reference materials allows USGS scientists and outside customers to examine a greater range of sample types while maintaining a high degree of data reliability.
Learn More
link
MC-ICP-MS equipment

Macro and Micro Analytical Methods Development

The Macro and Micro Analytical Methods Development Project (MMAMD) provides access to the expertise of highly experienced research scientists and state of the art analytical instrumentation to develop new and unique analytical capabilities to solve complex problems beyond routine analysis.
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center
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Macro and Micro Analytical Methods Development

The Macro and Micro Analytical Methods Development Project (MMAMD) provides access to the expertise of highly experienced research scientists and state of the art analytical instrumentation to develop new and unique analytical capabilities to solve complex problems beyond routine analysis.
Learn More

Results from geochemical and mineralogical characterization of Boquillas Shale geochemical reference material ShBOQ-1

This data release accompanies a Fact Sheet on the ShBOQ-1 geochemical reference material (Birdwell and Wilson, 2021). Average and standard deviations reported in the Fact Sheet were calculated using the values compiled here.
By
Central Energy Resources Science Center

Geologic Map of MTM -20012 and -25012 Quadrangles, Margaritifer Terra Region of Mars

Mars Transverse Mercator (MTM) -20012 and -25012 quadrangles (lat 17.5 deg - 27.5 deg S., long 345 deg - 350 deg E.) cover a portion of Margaritifer Terra near the east end of Valles Marineris. The map area consists of a diverse assemblage of geologic surfaces including isolated knobs of rugged mountainous material, heavily cratered and dissected ancient highland material, a variety of plains mate
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Natural Hazards Mission Area, Astrogeology Science Center, Planetary Geologic Mapping

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