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reference materials and laboratory equipment
USGS reference material matrix sampling, geochemical reference materials, analytical laboratory equipment, and sample data. Photographs by USGS.

Science Issue and Relevance

Many projects funded by the Minerals Resources Program and other USGS mission areas use chemical analysis as a tool to study a variety of mineralogical, ecological, environmental, and biological processes. Routinely, the success of these projects is reliant upon access to state-of-the-art instrumentation and methods of analysis. The Macro and Micro Analytical Methods Development Project 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. Generally macro analytical methods examine the bulk elemental, chemical, or mineralogical composition of a sample while micro analytical methods use specialized sample introduction devices or instrumentation to examine how the elements or minerals are spatially distributed in a sample. Both macro and micro analytical methods use a variety of analytical instrumentation including: Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), X-ray Fluorescence (XRF), X-ray Diffraction (XRD), Raman Spectroscopy, and Cavity Ring-Down Spectroscopy (CRDS). Development of new, state-of-the-art analytical methods can be applied to topical studies in energy and minerals, environmental health, ecosystems, land resources use, water quality, and natural hazards. For many projects carried out by the USGS, there are no commercial laboratories that can provide the unique types of geochemical analyses or the high quality data required to carry out the project objectives.

Our Methodology

Our scientists ascertain what types of new and emerging analytical techniques USGS will need with the next several years to support programmatic research efforts and to develop those techniques using existing instrumentation or by obtaining the necessary equipment and instrumentation. Another key goal of the project is to evaluate the need for and develop new natural matrix geochemical standard reference materials that are used by USGS and other scientists to calibrate analytical instrumentation, validate methods and models, and monitor laboratory performance. Project members also develop methods for specialized analyses via reimbursable projects for other DOI and U.S. government agencies. The Project is responsible for mainting the availability of analytical instrumentation, laboratories, techniques and staffing for use by multiple USGS projects and for maintaining specialized in-house capabilities for use in characterization of difficult to analyze sample matrices beyond the capabilities of the contract laboratory.

New Macro Analytical Methods Development

Contacts: Chris Mills (acting), and Michael Pribil (acting)

USGS analytical equipment
A selection of the analytical equipment in USGS laboratories. Photographs by USGS.

This task provides for the coordinated research and development of new analytical methods needed to meet the needs of projects administered under the Mineral Resources Program and other USGS projects as needs arise. Project staff work on analytical techniques including inductively coupled plasma-atomic emission spectrometry (ICP-AES), inductively coupled plasma-mass spectrometry (ICP-MS), ion chromatography, liquid chromatography, hydride generation atomic absorption, and specific element instrumentation such as mercury, carbon, and sulfur analyzers. Other areas of investigation include development of new or improved sample preparation methodologies such as specialized hot plate or microwave-assisted digestions and extractions to improve efficiency and data quality.

One of the primary goals of this task is to develop and validate analytical protocols for difficult-to-analyze samples that are beyond the capabilities of routine commercial laboratories. Development of new analytical protocols is performed in anticipation of future analytical needs of USGS projects, so that state-of-the-art analytical methods will be available to project staff as they are needed. Current areas of focus include:

  1. Development and validation of new analytical methodologies including High Resolution Dynamic Reaction Cell (DRC) and/or Kinetic Energy Discrimination (KED) Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for analysis of typical geological samples to improve detection limits and accury eliminating common interferences on elements,
  2. Development and validation of direct analysis of powdered samples for trace elements using Energy Dispersive X-ray Fluorescence (EDXRF),
  3. Development and validation of new analytical methods for interference-free analysis of rare earth elements in waters, soils, and sediments using alternative sample introduction devices, dynamic reaction cell ICP-MS, and/or high resolution (HR) ICP-MS,
  4. Continued development of speciation methods using the high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) system for determination of different forms of arsenic, selenium, and chromium species in aqueous species,
  5. Continued investigation and validation of new methods for the preservation and extraction of inorganic species of arsenic, selenium, and chromium from a wide variety of sample types, including fire ashes, soils, sediments, and air filters, including improved or modified hexavalent chromium extraction methods,
  6. Investigation and development of isotope dilution methodologies for the accurate determination of elements in geochemical reference materials,
  7. Continued development and validation of new and improved analytical methods using dual-view ICP-AES to improve detection limits and elimination of interferences using Multicomponent Spectral Fitting (MSF) techniques,
  8. Further develop novel in-situ microanalytical techniques for determining trace concentrations in heavy metals in surface water environments in virtual real-time mode using field deployable instrumentation that operates in unattended mode.


Breit, G.N., Hunt, A.G., Wolf, R.E., Koenig, A.E., Fifarek, R.H., and Coolbaugh, M.F., 2011, Are modern geothermal waters in northwest Nevada forming epithermal gold deposits?, in, Steininger, R. and Pennell, B., eds., Geological Society of Nevada Symposium 2010, Great Basin Evolution and Metallogeny, Volume II: Lancaster, Pennsylvania, DEStech Publications, Inc., p. 833-844.

Chesnik, I.E., Centeno, J.A., Todorov, T.I., Koenig, A.E., and Potter, Kimberlee, 2011, Spatial mapping of mineralization with manganese-enhanced magnetic resonance imaging: Bone, 48(5), p. 1194-1205, doi:10.1016/j.bone.2011.02.014.

Crock, J.G., Smith, D.B., Yager, T.J.B., Berry, C.J., and Adams, M.G., 2011, Analytical results for municipal biosolids samples from a monitoring program near Deer Trail, Colorado (U.S.A.), 2010: U.S. Geological Survey Open-File Report 2011–1146, 24 p.,

Crock, J.G., and Lamothe, P.J., 2011, Inorganic chemical analysis of environmental materials—A lecture series: U.S. Geological Survey Open-File Report 2011–1193, 117 p.,

Goldstein, H.L., Breit, G.N., Yount, J.C., Reynolds, R.L., Reheis, M.C., Skipp, G.L., Fisher, E.M., and Lamothe, P.J., 2011, Physical, chemical, and mineralogical data from surficial deposits, groundwater levels, and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada: U.S. Geological Survey Data Series 607, 153 p.,

Gough, L.P., Lamothe, P.J., Sanzolone, R.F., Drew, L.J., and Maier, J.A.K., 2009, The regional geochemistry of soils and willow in a metamorphic bedrock terrain, Seward Peninsula, Alaska, 2005, and its possible relation to moose: U.S. Geological Survey Open-File Report 2009-1124, 41 p.,

Hédouin, L.S., Wolf, R.E., Phillips, Jeff, and Gates, R.D., 2016, Improving the ecological relevance of toxicity tests on scleractinian corals: Influence of season, life stage, and seawater temperature: Environmental Pollution, 213, p. 240-253, doi: 10.1016/j.envpol.2016.01.086.

Kraus, J.M., Schmidt, T.S., Walters, D.M., Wanty, R.B., Zuellig, R.E., and Wolf, R.E., 2014, Cross-ecosystem impacts of stream pollution reduce resource and contaminant flux to riparian food webs: Ecological Applications, 24(2), p. 235-243, doi:10.1890/13-0252.1.

Migaszewski, Z.M., Crock, J.G., Lamothe, P.J., GaŁuszka, A., and Dołęgowska, S., 2011, The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies: Environmental Chemistry Letters, 9(3), p. 323-329, doi:10.1007/s10311-010-0282-2.

Migaszewski, Z.M., GaŁuszka, A., Crock, J.G., Lamothe, P.J., and Dołęgowska, S., 2009, Interspecies and interregional comparisons of the chemistry of PAHs and trace elements in mosses Hylocomium splendens (Hedw.) B.S.G. and Pleurozium schreberi (Brid.) Mitt. from Poland and Alaska: Atmospheric Environment, 43(7), p. 1464-1473, doi:10.1016/j.atmosenv.2008.11.035.

Migaszewski, Z.M., GaŁuszka, A., DoŁęgowskaa, S., Crock, J.G., and Lamothe, P.J., 2010, Mercury in mosses Hylocomium splendens (Hedw.) B.S.G. and Pleurozium schreberi (Brid.) Mitt. from Poland and Alaska: Understanding the origin of pollution sources: Ecotoxicology and Environmental Safety, 73(6), p. 1345-1351, doi:10.1016/j.ecoenv.2010.06.015.

Plumlee, G.S., Durant, J.T., Morman, S.A., Neri, Antonio, Wolf, R.E., Dooyema, C.A., Hageman, P.L., Lowers, H.A., Fernette, G.L., Meeker, G.P., Benzel, W.M., Driscoll, R.L., Berry, C.J., Crock, J.G., Goldstein, H.L., Adams, Monique, Bartrem, C.L., Tirima, Simba, Behbod, Behrooz, von Lindern, Ian, and Brown, Mary Jean, 2013, Linking Geological and Health Sciences to Assess Childhood Lead Poisoning from Artisanal Gold Mining in Nigeria: Environmental Health Perspectives, 121(6), p. 744-750, doi:10.1289/ehp.1206051.

Plumlee, G.S., Morman, S.A., Meeker, G.P., Hoefen, T.M., Hageman, P.L., and Wolf, R.E., 2014, 11.7– The Environmental and Medical Geochemistry of Potentially Hazardous Materials Produced by Disasters, in Lollar, B.S.L. (ed.), Treatise on Geochemistry (Second Edition), Volume 11: Environmental Geochemistry, p. 257-304, doi:10.1016/B978-0-08-095975-7.00907-4.

Schmidt, T.S., Clements, W.H., Zuellig, R.E., Mitchell, K.A., Church, S.E., Wanty, R.B., San Juan, C.A., Adams, Monique, and Lamothe, P.J., 2011, Critical tissue residue approach linking accumulated metals in aquatic insects to population and community-level effects: Environmental Science and Technology, 45(16), p. 7004-7010, doi:10.1021/es200215s.

Todorov, T.I., Wolf, R.E., and Adams, Monique, 2014, Multi-elemental analysis of aqueous geological samples by inductively coupled plasma-optical emission spectrometry: U.S. Geological Survey Open-File Report 2014–1067, 21 p.,

Verplanck, P.L., Furlong, E.T., Gray, J.L., Phillips, P.J., Wolf, R.E., and Esposito, Kathleen, 2010, Evaluating the Behavior of Gadolinium and Other Rare Earth Elements though Large Metropolitan Sewage Treatment Plants: Environmental Science and Technology, 44(10), p. 3876-3882, doi:10.1021/es903888t.

Verplanck, P.L., Manning, A.H., Graves, J.T., McCleskey, R.B., Todorov, Todor, and Lamothe, P.J., 2010, Geochemistry of Standard Mine waters, Gunnison County, Colorado, July 2009: U.S. Geological Survey Open-File Report 2009–1292, 21 p.,

Wanty, R.B., Balistrieri, L.S., Wesner, J.S., Walters, D.M., Schmidt, T.S., Podda, F., De Giudici, G., Stricker, C.A., Kraus, J., Lattanzi, P., Wolf, R.E., and Cidu, R., 2015, Isotopic insights into biological regulation of zinc in contaminated systems: Procedia Earth and Planetary Science, 13, p. 60-63, doi:10.1016/j.proeps.2015.07.014.

Wolf, R.E., and Adams, Monique, 2015, Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS): U.S. Geological Survey Open-File Report 2015–1010, p. 34,

Wolf, R.E., Hoefen, T.M., Hageman, P.L., Morman, S.A., and Plumlee, G.S., 2010, Speciation of arsenic, selenium, and chromium in wildfire impacted soils and ashes: U.S. Geological Survey Open-File Report 2010–1242, 29 p.,

Wolf, R.E., Morman, S.A., Hageman, P.L., Hoefen, T.M., and Plumlee, G.S., 2011, Simultaneous speciation of arsenic, selenium, and chromium: species stability, sample preservation, and analysis of ash and soil leachates: Analytical and Bioanalytical Chemistry, 401(9), Article: 2733, doi:10.1007/s00216-011-5275-x.

Wolf, R.E., Morrison, J.M., and Goldhaber, M.B., 2007, Simultaneous determination of Cr(III) and Cr(VI) using reversed-phased ion-pairing liquid chromatography with dynamic reaction cell inductively coupled plasma mass spectrometry: Journal of Analytical Atomic Spectrometry, 22, p. 1051-1060, doi:10.1039/B704597B.

Wolf, R.E., and Wilson, S.A., 2010, Evaluation of extraction methods for hexavalent chromium determination in dusts, ashes, and soils: U.S. Geological Survey Open-File Report 2010–1243, 22 p.,

Yager, T.J.B., Smith, D.B., and Crock, J.G., 2011, Biosolids, crop, and groundwater data for a biosolids-Application area near Deer Trail, Colorado, 2007 and 2008: U.S. Geological Survey Data Series 589, 53 p.,

Geological Reference Materials

Contact: Steve Wilson,, 303-236-2454

USGS reference materials
USGS Geological Reference Materials are natural matrix materials that have been well characterized for their chemical composition. Photograph by USGS.

This task develops and produces geochemical reference materials in support of USGS mineral exploration and development activities. Geological reference materials are crucial for USGS projects and laboratories to ensure the highest possible accuracy of their chemical analyses.

Geologic reference materials are developed using matrix matched geologic sample types currently under investigation. Well characterized reference materials are a key component in evaluating laboratory accuracy and precision, as these materials are routinely used in laboratory quality assurance programs. We provide reference materials for methods development on new sample types or methods of analysis, which in turn allow the transition from qualitative to quantitative analysis. We foster development of new preparation techniques to meet specific project needs and collaborate with government, private, and international partners to develop new reference materials that benefit USGS activities.

The major areas of investigation are listed below.

  1. Replacement of existing USGS powdered reference materials which serve as the backbone to many quality control programs.
  2. Development of new reference materials for microanalysis, particularly focusing on the development of a) glass materials from different alumino silicate rock types and b) pressed powders from significant geologic matrix types (phosphates, gympsum, barite, sulfides, carbonates).
  3. Development of new reference materials from sample types impotant in rare earth element source materials (carbonatite, alkaline dike).
  4. Develop plans for the preparation of several shale gas reference materials in collaboration with industry.
  5. Begin developing a series of new geologic reference materials designed to assist in the mineralogical analysis of geologic materials by X-ray diffraction (XRD).
  6. Prepare customized geologic reference materials for private and government customers (ex. mine waste, ore material, baseline sediments, soils, lunar simulant).

For additional information see these related sites:


Jochum K.P., Scholz D., Stoll B., Weis U., Wilson S.A., Yang Q., Schwalb A., Börner, N., Jacob D.E., and Andreae M.O., 2012, Accurate trace element analysis of speleothems and biogenic calcium carbonates by LA-ICP-MS: Chemical Geology, 318-319, p. 31-44, doi:10.1016/j.chemgeo.2012.05.009.

Nagourney, S.J., Wilson, S.A., Buckley, B., Kingston, H.M.S., Yang, S., and Long, S.E., 2008, Development of a standard reference material for Cr(VI) in contaminated soil: Journal of Analytical Atomic Spectrometry, 23(11), p. 1550-1554, doi:10.1039/B808488B.

Nagourney, S.J., Wilson, S.A., and Long, S.E., 2016, Using reference materials to improve the quality of data generated by USEPA analytical methods: Environmental Science: Processes & Impacts, 18, p. 1477-1483, doi:10.1039/C6EM00438E.

collecting materials in field
preparing reference material
Base material is collected from the field and processed in the laboratory to create a geologic reference material. Photographs by USGS.

Laser Ablation ICP-MS Trace Element Microanalysis

Contact: Alan Koenig,, 303-236-2475

USGS scientists in the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) laboratory in Denver, CO. Photograph by USGS.

The laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) task involves the continuing advance of in-situ methods for trace element analyses for Mineral Resource Program goals. Direct, in-situ analyses provide a detailed look at the chemical story preserved in minerals, rocks, biological and environmental samples. Our work provides broad support across numerous USGS projects and to outside collaborators. Focus areas include the direct assessment of the residence and mode of occurrence of critical metals in a variety of deposit types and waste products, utilization of trace element signatures and zoning within minerals to better decipher mineral deposit origins, and detailed examination of the role of microchemistry and complex residence of metals on the geometallurgy and processing of geologic materials for economic recoveries.

Our objectives are to maintain the laboratory as a leading analytical facility providing analyses for core USGS projects, be responsive (and proactive) to the changing needs of projects and scientists in areas where microanalyses can help solve problems, and to integrate and understand the complimentary nature of both traditional bulk chemical methods as well as the important necessary microanalytical tools. We utilize the known and newly devloping potential of trace element microanalysis for the determination of trace elements in minerals and other solid media useful to attain programmatic goals. We work closely with the Geological Reference Materials task and the other microanalytical techniques in this project.


Chen, L., Li, X., Li, J., Hofstra, A.H., Liu, Y., Alan E. Koenig, A.E., 2015, Extreme variation of sulfur isotopic compositions in pyrite from the Qiuling sediment-hosted gold deposit, West Qinling orogen, central China: an in situ SIMS study with implications for the source of sulfur: Mineralium Deposita, 50(6), p. 643-656, doi:10.1007/s00126-015-0597-9.

Depiné, M., Frimmel, H.E., Emsbo, P., Koenig, A.E., and Kern, M., 2013, Trace element distribution in uraninite from Mesoarchaean Witwatersrand conglomerates (South Africa) supports placer model and magmatogenic source: Mineralium Deposita, 48(4), p. 423-435, doi:10.1007/s00126-013-0458-3.

Emsbo, P., McLaughlin, P.I., Breit, G.N., du Bray, E.A., and Koenig, A.E., 2015, Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?: Gondwana Research, 27(2), p. 776-785, doi:10.1016/

Gibson-Reinemer, D.K., Johnson, B.M., Martinez, P.J., Winkelman, D.L., Koenig, A.E., and Woodhead, J.D., 2009, Elemental signatures in otoliths of hatchery rainbow trout (Oncorhynchus mykiss): distinctiveness and utility for detecting origins and movement: Canadian Journal of Fisheries and Aquatic Sciences, 66(4), p. 513-524, doi:10.1139/F09-015.

Graham, G.E., Kelley, K.D., Slack, J.F., and Koenig, A.E., 2009, Trace elements in Zn–Pb–Ag deposits and related stream sediments, Brooks Range Alaska, with implications for Tl as a pathfinder element: Geochemistry: Exploration, Environment Analysis, 9, p. 19-37, doi:10.1144/1467-7873/08-177.

Koenig, A.E., Rogers, R.R., and Trueman, C.N., 2009, Visualizing fossilization using laser ablation–inductively coupled plasma–mass spectrometry maps of trace elements in Late Cretaceous bones: Geology, 37(6), p. 511-514, doi:10.1130/G25551A.1.

Kolker, A., Senior, C., van Alphen, C., Koenig, A., and Geboy, N., In Press, Corrected Proof, Mercury and trace element distribution in density separates of a South African Highveld (#4) coal: Implications for mercury reduction and preparation of export coal: International Journal of Coal Geology, Available online 6 February 2016, doi:10.1016/j.coal.2016.02.002.

Nadoll, P., and Koenig, A.E., 2011, LA-ICP-MS of magnetite: methods and reference materials: Journal of Analytical Atomic Spectrometry, 26, p. 1872-1877, doi:10.1039/C1JA10105F.

Nadoll, P., Mauk, J.L., Hayes, T.S., Koenig, A.E., and Box, S.E., 2012, Geochemistry of magnetite from hydrothermal ore deposits and host rocks of the Mesoproterozoic Belt Supergroup, United States: Economic Geology, 107(6), p. 1275-1292, doi:10.2113/econgeo.107.6.1275.

Nadoll, P., Mauk, J.L., Leveille, R.A., and Koenig, A.E., 2015, Geochemistry of magnetite from porphyry Cu and skarn deposits in the southwestern United States: Mineralium Deposita, 50(4), p. 493–515, doi:10.1007/s00126-014-0539-y.

O'Brien, J.J., Spry, P.G., Teale, G.S., Jackson, S.E., and Koenig, A.E., 2015, Gahnite composition as a means to fingerprint metamorphosed massive sulfide and non-sulfide zinc deposits: Journal of Geochemical Exploration, (159), p. 48-61, doi:10.1016/j.gexplo.2015.08.005.

Prouty, N.G., Roark, E.B., Koenig, A.E., Demopoulos, A.W.J., Batista, F.C., Kocar, B.D., Selby, D., McCarthy, M.D., Mienis, F., and Ross, S.W., 2014, Deep-sea coral record of human impact on watershed quality in the Mississippi River Basin: Global Biogeochemical Cycles, 28, p. 29-43, doi:10.1002/2013GB004754.

Ridley, W.I., Pribil, M.J., Koenig, A.E., and Slack, J.F., 2015, Measurement of in Situ Sulfur Isotopes by Laser Ablation Multi-Collector ICPMS: Opening Pandora's Box: Procedia Earth and Planetary Science, 13, p. 116-119, doi:10.1016/j.proeps.2015.07.028.

Rogers, R.R., Fricke, H.C., Addona, V., Canavan, R.R., Dwyer, C.N., Harwood, C.L., Koenig, A.E., Murray, R., Thole, J.T., and Williams, J., 2010, Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) To Explore Geochemical Taphonomy of Vertebrate Fossils in the Upper Cretaceous Two Medicine and Judith River Formations of Montana: Palaios 25(3), p. 183-195, doi:10.2110/palo.2009.p09-084r.

Rusk, B., Koenig, A. and Lowers, H., 2011, Visualizing trace element distribution in quartz using cathodoluminescence, electron microprobe and laser ablation-inductively coupled plasma-mass spectrometry: American Mineralogist, 96, p. 703-708, doi:10.2138/am.2011.3701.

Schuchert, P.C., Arkhipkin, A.I., and Koenig, A.E., 2010, Traveling around Cape Horn: Otolith chemistry reveals a mixed stock of Patagonian hoki with separate Atlantic and Pacific spawning grounds: Fisheries Research, 102(1-2), p. 80-86, doi:10.1016/j.fishres.2009.10.012.

Stowell, H., Parker, K.O., Gatewood, M., Tulloch, A., and Koenig, A., 2014, Temporal links between pluton emplacement, garnet granulite metamorphism, partial melting and extensional collapse in the lower crust of a Cretaceous magmatic arc, Fiordland, New Zealand: Journal of Metamorphic Geology, 32, p. 151-175, doi:10.1111/jmg.12064.

Stowell, H., Tulloch, A., Zuluaga, C., and Koenig, A., 2010, Timing and duration of garnet granulite metamorphism in magmatic arc crust, Fiordland, New Zealand: Chemical Geology, 273(1-2), p. 91-110, doi:10.1016/j.chemgeo.2010.02.015.

Multi-Collector ICP-MS

Contact: Michael Pribil

USGS Nu Plasma HR multi-collector inductively coupled plasma-mass spectrometer in Denver, CO. Photograph by M. Pribil.

The objectives for the multi-collector inductively coupled plasma-mass spectrometer (MC-ICP-MS) lab are to continue the development of new methodologies for analysis and application of isotope systems in both solution and solid (laser) form for the applications in mineral and environmental research in support of Mineral Resources Program and USGS goals. The primary objective is to better understand the potential insight that non-traditional and traditional stable isotopes can provide for the Program's environmental, economic and geological studies. The infancy of multi-collectors still warrants the need for thorough method development with a focus on chromatographic separation for solution sample introduction and in situ laser ablation introduction. These new methods will have immediate application in the Mineral Resources Program and the multi-collector field. The lab will continue to establish new ties within the USGS and with other State, Federal agencies and Universities.

Isotope System Capabilities

pyrite grain
Pyrite grain with δ34S isotopic composition. Photograph by M. Pribil.
  • δ34S and δ33S isotopic compositions by solution and laser ablation
  • Sr isotopic composition by solution and laser ablation
  • Pb isotopic composition by solution and laser ablation
  • Hg isotopic composition
  • Cu, Fe and Zn isotopic compositions

Current Research Endeavors

Sr in situ laser ablation of fish otolith. Image by M. Pribil.
  • In situ S isotope ratios by laser ablation MC-ICP-MS for geological applications
  • Sr in situ laser ablation of fish otoliths and whole otolith by solution
  • Development of in situ Pb isotope glass reference material
  • Source correlation using multiple isotope systems
  • Hg isotope systematics in mineral deposits and ecosystems
multi-collector ICP-MS
USGS Nu Plasma II multi-collector inductively coupled plasma-mass spectrometer in Denver, CO. Photograph by M. Pribil.


Berger, B.R., Henley, R.W., Lowers, H.A., and Pribil, M.J., 2014, The Lepanto Cu–Au deposit, Philippines: A fossil hyperacidic volcanic lake complex: Journal of Volcanology and Geothermal Research, 271, p. 70-82, doi:10.1016/j.jvolgeores.2013.11.019.

Bern, C.R., Chadwick, O.A., Kendall, C., and Pribil, M.J., 2015, Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems: Science of the Total Environment, 514, p. 250-260, doi:10.1016/j.scitotenv.2015.02.001.

Gray, J.E., Pribil, M.J., and Higueras, P.L., 2013, Mercury isotope fractionation during ore retorting in the Almadén mining district, Spain: Chemical Geology, 357, p. 50-157, doi:10.1016/j.chemgeo.2013.08.036.

Gray, J.E., Pribil, M.J., Van Metre, P.C., Borrok, D.M., and Thapalia, A., 2013, Identification of contamination in a lake sediment core using Hg and Pb isotopic compositions, Lake Ballinger, Washington, USA: Applied Geochemistry, 29, p. 1-12, doi:10.1016/j.apgeochem.2012.12.001.

Gray, J.E., Van Metre, P.C., Pribil, M.J., and Horowitz, A.J., 2015, Tracing historical trends of Hg in the Mississippi River using Hg concentrations and Hg isotopic compositions in a lake sediment core, Lake Whittington, Mississippi, USA: Chemical Geology, 395, p. 80-87, doi:10.1016/j.chemgeo.2014.12.005.

Gray, J.E., Van Metre, P.C., Pribil, M.J., and Horowitz, A.J., 2015, Corrigendum to “Tracing historical trends of Hg in the Mississippi River using Hg concentrations and Hg isotopic compositions in a lake sediment core": Chemical Geology, 404, p. 183, doi:10.1016/j.chemgeo.2015.04.014.

Harmon, R.S., Wörner, G., Pribil, M.J., Kern, Z., István, F., Lyons, W.B., Gardner, C.B., and Goldsmith, S.T., 2015, Isotopic Geochemistry of Panama Rivers: Procedia Earth and Planetary Science, 13, p. 108-111, doi:10.1016/j.proeps.2015.07.026.

Pribil, M.J., Maddaloni, M.A., Staiger, K., Wilson, E., Magriples, N., Mustafa, A., and Santella, D., 2011, Investigation of off-site airborne transport of lead from a superfund removal action site using lead isotope ratios and concentrations: Applied Geochemistry, 41, p. 89-94, doi:10.1016/j.apgeochem.2013.11.004.

Pribil, M.J., Ridley, W.I., and Emsbo, P., 2015, Sulfate and sulfide sulfur isotopes (δ34S and δ33S) measured by solution and laser ablation MC-ICP-MS: An enhanced approach using external correction: Chemical Geology, 412, p. 99-106, doi:10.1016/j.chemgeo.2015.07.014.

Pribil, M.J., Wanty, R.B., Ridley, W.I., and Borrok, D.M., 2010, Influence of sulfur-bearing polyatomic species on high precision measurements of Cu isotopic composition: Chemical Geology, 272(1-4), p. 49-54, doi:10.1016/j.chemgeo.2010.02.003.

Ridley, W.I., Pribil, M.J., Koenig, A.E., and Slack, J.F., 2015, Measurement of in Situ Sulfur Isotopes by Laser Ablation Multi-Collector ICPMS: Opening Pandora's Box: Procedia Earth and Planetary Science, 13, p. 116-119, doi:10.1016/j.proeps.2015.07.028.

Witt, E.C. III, Pribil, M.J., Hogan, J.P., and Wronkiewicz, D.J., 2016, Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district: Environmental Pollution, 216, p. 450-459, doi:10.1016/j.envpol.2016.05.070.

Method for Assessing the Microbial Geochemistry of Mineral Deposits and Their Impact on Surrounding Environments

biogeochemistry laboratory equipment
Analytical equipment, including gas chromatographs and spectrometers, in the USGS microbial geochemistry laboratory in Denver, CO. Photographs by Christopher Mills, USGS.

Contact: Kate Campbell,, 303-541-3035, and Christopher Mills

The transport and fate of metals are inextricably linked to the carbon cycle. Natural organic compounds chelate metals which is key to the sequestration and transport of metals in aquatic environments. Many types of microorganisms in soil, sediment, and water environments link the oxidation of organic carbon and the reduction of metals. Others mediate the oxidation or methylation of metals. Many of the processes that release metals into the environment from mineralized deposits or mine waste are exclusively mediated or are accelerated by microbial activity. In addition, microbial activity can mitigate (e.g. Cr[VI] reduction) or exacerbate (e.g. mercury methylation) trace metal pollution. Micoorganisms also respond to toxic concentrations of trace metals and changes in microbial community structure can be an indicator of impacts to ecosystem health. Organic biomarker molecules isolated from environmental matrices can indicate the types and abundances of microorganisms present. Some indicator molecules provide measures of viable microorganisms while others can integrate long-term occurrence of microbial processes.

We maintain and develop expertise in microbial biogeochemistry and associated analytical methods and instrumentation to support research on processes that distribute and sequester trace metals from mined and unmined mineralized deposits. The methods will be applied to geochemical exploration research and on environmental impacts of mining. We will develop methods that utilize gas chromatography-mass spectrometry to measure microbial abundance and characterize microbial communities.


  • Two Picarro cavity-ringdown spectrometers for precise determination of the stable isotopic composition of several gas-phase species. Advantages of this technology over traditional isotope ratio mass spectrometry techniques are lower cost, greater portability, and less need for pure gas samples.
    • L2130-i measures the δ18O and δ2H values of water
    • G2201-i measures the concentrations and δ13C ratios of CO2 and CH4 in gas samples.
  • Agilent 7890 gas chromatograph with a 5975C mass selective detector and flame ionization detector. Used to analyze microbial membrane phospholipid fatty acids (PLFAs) to quantify viable microbial abundance and monitor changes in microbial community.
  • SRI-8610C gas chromatograph designed to measure concentrations of permanent (e.g. O2, N2) and reactive gasses (e.g. CH4) in soil gas samples.


Centeno J.A., Todorov T.I., van der Voet, G.B., and Mullick, F.G., 2010, 6. Metal Toxicology in Clinical, Forensic and Chemical Pathology, in Analytical Techniques for Clinical Chemistry: Methods and Applications (eds S. Caroli and G. Záray), John Wiley & Sons, Inc., Hoboken, NJ, USA, doi:10.1002/9781118271858.ch6

Ives, J.A., Moffett, J.R., Arun, P., Lam, D., Todorov, T.I., Brothers, A.B., Anick, D.J., Centeno, J.,Namboodiri, M.A.A., and Jonas, W.B., 2010, Enzyme stabilization by glass-derived silicates in glass-exposed aqueous solutions: Homeopathy, 99(1), p. 15-24, doi:10.1016/j.homp.2009.11.006.

Mills, C.T., Bern, C.R., Wolf, R.E., Foster, A.L., Morrison, J.M., and Benzel, W.M., 2017, Modifications to EPA Method 3060A to Improve Extraction of Cr(VI) from Chromium Ore Processing Residue-Contaminated Soils: Environmental Science and Technology, 51(19), p. 11235-11243, doi:10.1021/acs.est.7b01719.

Mills, C.T., and Goldhaber, M.B., 2012, Laboratory investigations of the effects of nitrification-induced acidification on Cr cycling in vadose zone material partially derived from ultramafic rocks: Science of the Total Environment, 435-436, p. 363-373, doi:10.1016/j.scitotenv.2012.06.054.

Mills, C.T., and Goldhaber, M.B., 2010, On silica-based solid phase extraction techniques for isolating microbial membrane phospholipids: Ensuring quantitative recovery of phosphatidylcholine-derived fatty acids: Soil Biology and Biochemistry, 42(7), p. 1179-1182, doi:10.1016/j.soilbio.2010.03.023.

Sarafanov, A.G., Todorov, T.I., Centeno, J.A., Macias, V., Gao, W., Liang, W., Beam, C., Gray, M.A., and Kajdacsy-Balla, A.A., 2011, Prostate cancer outcome and tissue levels of metal ions: The Prostate, 71(11), p. 1231-1238, doi:10.1002/pros.21339.

Raman Spectroscopy for Metal Speciation in Minerals

Contact: Andrea Foster,, 650-329-5437

Currently the best available method for the direct quantification of chromium(VI) in environmental solids (e.g. soils, rocks, mine wastes, manufacturing residues, and materials in the built environment) is synchrotron-based X-ray absorption near edge spectroscopy (XANES), a technique with very limited availability and no potential for application on a routine basis. Several laboratory-based techniques now exist that show promise for routine quantification of chromium(VI) in solids at trace levels: Raman spectroscopy, wavelength-dispersive X-ray fluoresence (WD-XRF), and laboratory-based XANES. The individual capabilities of each of these techniques for chromium(VI) quantification and chromium speciation in solids will be assessed in this task by analyzing selected representatives of an extensive set of samples prepared under a previous project. Raman spectroscopy is a spectroscopic technique used to observe vibrational, rotational, and other low-frequency modes in a system and is commonly used in chemistry to provide a fingerprint by which molecules can be identified. Raman spectroscopy could provide an alternative method to X-ray absorption near edge structure XANES for the determination of oxidation state of elements (e.g. arsenic and chromium) directly in the solid. This would allow studies to be performed more easily with lab-based instrumentation.

Our objectives are:

  • Use microbeam techniques to identify chromium-bearing phases in soils contaminated with chromite-ore processing residue, in naturally-weathered serpentinite soils, and in primary serpentinite / peridotite rock.
  • Test the feasibility of above-mentioned laboratory-based techniques to quantify chromium(VI) species in solid phases and microvolumes of solution.


Verplanck, P.L., Furlong, E.T., Gray, J.L., Phillips, P.J., Wolf, R.E., and Esposito, K., 2010, Evaluating the behavior of gadolinium and other rare earth elements through large metropolitan sewage treatment plants: Environmental Science and Technology, 44(10), p. 3876-3882, doi:10.1021/es903888t.

Research Mineralogy

Contact: Nadine Piatak,, 703-648-6254

XRD lab
USGS powdered x-ray diffraction laboratory in Reston, VA. Photograph by Nadine Piatak, USGS.

We provide research, development, and application of mineralogical analysis and support of topical projects within the USGS. The task includes x-ray mineralogy, thermogravimetric analysis coupled with quadruple mass spectrometry, qualitative and semi-quantitative x-ray fluorescence spectroscopy and related analytical techniques for mineralogical studies in support of Mineral Resources Program and Energy Resources Program projects. The powder x-ray diffraction laboratory in Reston, VA provides qualitative and quantitative powder x-ray diffraction (XRD) and energy-dispersive x-ray fluorescence (EDXRF). Capabilities include identification and quantification of crystalline and amorphous phases, and crystallographic and atomic structure analysis for a wide variety of sample media.

Task goals are to 1) ensure availability of state-of-the-art mineralogical analyses for scientists funded by the Mineral and Energy Resources Programs, 2) develop new methods and new applications of existing methods, and 3) minimize duplication of skills and equipment by sharing laboratory facilities with both Mineral and Energy Resources Programs.

Learn more about the Reston, VA Powder X-Ray Diffraction Laboratory.


Levitan, D.M., Hammarstrom, J.M., Gunter, M.E., Seal, R.R. II, Chou, I-M, and Piatak, N.M., 2009, Mineralogy of mine waste at the Vermont Asbestos Group mine, Belvidere Mountain, Vermont: American Mineralogist, 94, p. 1063-1066, doi:10.2138/am.2009.3258.

Piatak, N.M., Argue, D.M., Seal, R.R., II, Kiah, R.G., Besser, J.M., Coles, J.F., Hammarstrom, J.M., Levitan, D.M., Deacon, J.R., and Ingersoll, C.G., 2013, Aquatic assessment of the Pike Hill Copper Mine Superfund site, Corinth, Vermont: U.S. Geological Survey Scientific Investigations Report 2012–5288, 109 p. plus 14 apps. [separate files],

Piatak, N.M., Dulong, F.T., Jackson, J.C., and Folger, H.W., 2014, Powder X-ray diffraction laboratory, Reston, Virginia: U.S. Geological Survey Fact Sheet 2014–3063, 2 p.,

Piatak, N.M., Parsons, M.B., and Seal, R.R., II, 2015, Characteristics and environmental aspects of slag: A review: Applied Geochemistry, 57, p. 236-266, doi:10.1016/j.apgeochem.2014.04.009.

Piatak, N.M., and Seal, R.R., II, 2012, Mineralogy and environmental geochemistry of historical iron slag, Hopewell Furnace National Historic Site, Pennsylvania, USA: Applied Geochemistry, 27(3), p. 623-643, doi:10.1016/j.apgeochem.2011.12.011.

Piatak, N.M, and Seal, R.R., II, 2010, Mineralogy and the release of trace elements from slag from the Hegeler Zinc smelter, Illinois (USA): Applied Geochemistry, 25(2), p. 302-320, doi:10.1016/j.apgeochem.2009.12.001.

Seal, R.R., II, Kiah, R.G., Piatak, N.M., Besser, J.M., Coles, J.F., Hammarstrom, J.M., Argue, D.M., Levitan, D.M., Deacon, J.R., and Ingersoll, C.G., 2010, Aquatic assessment of the Ely Copper Mine Superfund site, Vershire, Vermont: U.S. Geological Survey Scientific Investigations Report 2010–5084, 131 p.,

Smith, D.B., Cannon, W.F., Woodruff, L.G., Solano, Federico, and Ellefsen, K.J., 2014, Geochemical and mineralogical maps for soils of the conterminous United States: U.S. Geological Survey Open-File Report 2014–1082, 386 p.,

Soeder, D.J., Enomoto, C.B., and Chermak, J.A., 2014, The Devonian Marcellus Shale and Millboro Shale: GSA Field Guides, 35, p. 129-160, doi:10.1130/2014.0035(05).

Valentine, B.J., Hackley, P.C., Enomoto, C.B., Bove, A.M., Dulong, F.T., Lohr, C.D., and Scott, K.R., 2014, Organic petrology of the Aptian-age section in the downdip Mississippi Interior Salt Basin, Mississippi, USA: Observations and preliminary implications for thermal maturation history: International Journal of Coal Geology, 131, p. 378-391, doi:10.1016/j.coal.2014.07.001.

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