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Overview

ICP-MS Machine in the project's Clean Lab
Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) machine, above. [PDF file, 327 KB]

Work is focused annually on collaborating with high-priority U.S. Geological Survey projects and other Federal and international agencies, and on providing radiogenic and stable isotope analyses to support mineral- and environmentally-related geologic investigations.

  • Radiogenic isotope techniques are used for analysis of materials, fluids, and fluid and solid inclusions from ancient and modern environments. Analytical procedures are improved and developed using thermal ionization mass spectrometry and inductively coupled plasma mass spectrometry for studies directed at: regional and site-specific metal mobilization, metal transport, redistribution processes, and sources of fluids for regional geologic, ore genesis, life-cycles, and environmental applications.
  • Stable isotope work includes developing new and refining existing analytical techniques for the following applications:
    1. oxygen isotope analysis of dissolved sulfate for studies of mine drainage, acid deposition and ecosystems;
    2. hydrogen isotope analysis of silicate and other hydrated minerals for studies of ore genesis; and
    3. sulfur isotope analysis of submilligram samples of sulfide and sulfate minerals using continuous-flow technology for environmental, ore genesis and ecosystem studies.
Scientist working in clean lab.
USGS clean lab in Reston, VA.
Photos of the project's Clean Lab in Reston (Cleanliness is defined based on the number of particles of a defined diameter per unit volume. According to U.S. Federal Standard, a Class 100 clean room must have no more than 100 particles of diameter 0.5 mm per cubic foot of air).

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Publications

Ayuso, R.A., 2010, Chapter N: Petrology of Associated Igneous Rocks, Isotope Geochemistry and Radiogenic Isotopes of Ore, in John, D.A., ed., Porphyry copper deposit model, chap. B of Mineral deposit models for resource assessment: U.S. Geological Survey Scientific Investigations Report 2010–5070–B, p. 100-107, http://pubs.usgs.gov/sir/2010/5070/b/.

Ayuso, R.A., and Foley, N.K., 2008, Anthropogenic and natural lead isotopes in Fe-hydroxides and Fe-sulfates in a watershed associated with arsenic-enriched groundwater, Maine, USA: Geochemistry: Exploration, Environment, and Analysis, 8, p. 77-89, doi:10.1144/1467-7873/07-153.

Ayuso, R.A., Foley, N.K., and Lipfert, G., 2008, Chapter Twelve – Lead isotopes as monitors of anthropogenic and natural sources affecting the surficial environment, in De Vivo, B., Belkin, H.E., and Lima, A., eds., Environmental Geochemistry; Site Characterization, Data Analysis and Case Histories, Elsevier, p. 287-316, doi:10.1016/B978-0-444-53159-9.00012-7.

Ayuso, R.A., Foley, N.K., Seal, R.R. II, Bove, M., Civitillo, D., Cosenza, A., and Grezzi, G., 2013, Lead isotope evidence for metal dispersal at the Callahan Cu-Zn-Pb mine: Goose Pond tidal estuary, Maine, USA: Journal of Geochemical Exploration, v. 126-127, p. 1-22, doi: 10.1016/j.gexplo.2012.12.013.

Ayuso, R., Haeussler, P, Bradley, D., Wandless, G., and Foley, N., 2009, The role of ridge subduction in determining the geochemistry and Nd-Sr-Pb isotopic evolution of the Kodiak batholith in southern Alaska: Tectonophysics, 464 (1-4), p. 137–163, doi: 10.1016/j.tecto.2008.09.029.

Ayuso, R.A., Karl, S.M., Slack, J.F., Haeussler, P.J., Bettenbender, P.E., Wandless, G.A., and Colvin, A.S., 2007, Oceanic Pb-Isotope Sources of Proterozoic and Paleozoic Volcanogenic Massive Sulfide Deposits on Prince of Wales Island and Vicinity, Southeastern Alaska: U.S. Geological Survey Professional Paper 1732-E, 20 p., http://pubs.usgs.gov/pp/pp1732/pp1732e/.

Ayuso, R.A., and Kelley, K.D., 2008, Radiogenic Isotope Studies, in Kelley, K.D., ed., Regional Fluid Flow and Basin Modeling: U.S. Geological Survey Circular 1319, p. 20-23, http://pubs.usgs.gov/circ/1319/.

Ayuso, R.A., Kelley, K.D., Eppinger, R.G., and Forni, F., 2013, Pb-Sr-Nd isotopes in surficial materials at the Pebble porphyry Cu-Au-Mo deposit, southwestern Alaska: Can the mineralizing fingerprint be detected through cover: Economic Geology, 108(3), p. 543-562, doi: 10.2113/econgeo.108.3.543.

Ayuso, R.A., Kelley, K.D., Leach, D.L., Young, L.E., Slack, J.F., Wandless, J.F., Lyon, A.M., and Dillingham, J.L., 2004, Origin of the Red Dog Zn-Pb-Ag Deposits, Brooks Range, Alaska: Evidence from Regional Pb and Sr Isotope Sources: Economic Geology, 99(7), p. 1533-1553, doi:10.2113/gsecongeo.99.7.1533.

Ayuso, R.A., and Schulz, K.J., 2003, Nd-Pb-Sr Isotope Geochemistry and Origin of the Ordovician Bald Mountain and Mount Chase Massive Sulfide Deposits, Northern Maine, in Goodfellow, W.D., and others, editors, Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick, and Northern Maine: Economic Geology Monograph 11, p. 611-630.

Ayuso, R.A., and Till, A.B., 2014, Geochemical and Nd-Sr-Pb isotopic evolution of metabasites from rifting of continental lithosphere, Seward Peninsula, Alaska, and implications for paleogeographic reconstruction Reconstruction of a late Proterozoic to Devonian continental margin sequence, northern Alaska; its paleogeographic significance, and contained base-metal sulfide deposits: Geological Society of America, Special Papers, 506, p. 133-172, doi:10.1130/2014.2506(05).

Ayuso, R.A., Till, A.B., Slack, J.F., and Forni, F., 2014, Pb isotope geochemistry of stratabound Zn-Pb(-Ag-Au-Ba-F) deposits and occurrences in the Nome Complex, Seward Peninsula, Alaska: Metal sources and regional comparisons: Geological Society of America, Special Papers, 506, p. 173-212, doi: 10.1130/2014.2506(07).

Ayuso, R., Tucker, R., Peters, S., Foley, N.K. Jackson, J., Robinson, S., and Bove, M., 2013, Preliminary radiogenic isotope study on the origin of the Khanneshin carbonatite complex, Helmand Province, Afghanistan: Journal of Geochemical Exploration, v. 133, p. 6-14. doi: 10.1016/j.gexplo.2013.06.012

Ayuso, R.A., Wooden, J.N., Foley, N.K., Seal, R.R., and Sinha, A.K., 2005, U-Pb Zircon Ages and Pb Isotope Geochemistry of Gold Deposits in the Carolina Slate Belt of South Carolina: Economic Geology, 100(2), p. 225-252, doi:10.2113/gsecongeo.100.2.225.

Ayuso, R.A., Wooden, J.N., Foley, N.K., Slack, J.F., Sinha, A.K., and Persing, H., 2003, Pb Isotope Geochemistry and U-Pb Zircon (SHRIMP-RG) Ages of the Bald Mountain and Mount Chase Massive Sulfide Deposits, Northern Maine: Mantle and Crustal Contributions in the Ordovician, in Goodfellow, W.D., and others, editors, Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick, and Northern Maine: Economic Geology Monograph 11, p. 589-610.

Bove, M.A., Ayuso, R.A., De Vivo, B., Lima, A., and Albanese, S., 2011, Geochemical and isotopic study of soils and waters from an Italian contaminated site: Agro Aversano (Campania): Journal of Geochemical Exploration, 109 (1-3), p. 38-50, doi: 10.1016/j.gexplo.2010.09.013.

Cortini, M., Ayuso, R.A., DeVivo, B., Holden, P., and Somma, R., 2004, Isotopic composition of Pb and Th in interplinian volcanics from Somma-Vesuvius volcano, Italy: Mineralogy and Petrology, 80(1), p. 83-96, doi:10.1007/s00710-003-0023-3.

Cosenza, A., Ayuso, R.A., Foley, N., Albanese, S., Lima, A., Messina, A., and De Vivo, B., 2012, The geogenic vs anthropogenic source of harmful element anomalies in the eastern-central sector of the Peloritani Mountains (Sicily, Italy): Rendiconti Online Della Soceità Geologica Italiana, 21(Supplement 1), p. 265-267, http://rendiconti.socgeol.it/244/fulltext.html?ida=826.

Cosenza, A., Lima, A., Ayuso, R.A., Foley, N.K., Albanese, S., Messina, A., and De Vivo, B., 2015, Soil geochemical survey of abandoned mining sites in the Eastern-Central Peloritani Mountains, Sicily, Italy: Geochemistry: Exploration, Environment, Analysis, 15(4), p. 361-372, doi:10.1144/geochem2014-307.

De Vivo, B., Somma, R., Ayuso, R., Calderoni, G., Lima, A., Pagliuca, S., and Sava,A., 2002, Pb isotopes and toxic metals in floodplain and stream sediments from the Volturno River basin, Italy: Environmental Geology, 41(1), p. 101-112, http://dx.doi.org/10.1007/s002540100349.

Di Martino, C., Forni, F., Frezzotti, M.L., Palmeri, R., Webster, J.D., Ayuso, R.A., Lucchi, F., and Tranne, C.A., 2011, Formation of cordierite-bearing lavas during anatexis in the lower crust beneath Lipari Island (Aeolian arc, Italy): Contributions to Mineralogy and Petrology, 162(5), p. 1011-1030, doi:10.1007/s00410-011-0637-0.

Foley, N.K., and Ayuso, R.A., 2015, REE Enrichment in granite-derived regolith deposits of the Southeastern United States: Prospective source rocks and accumulation processes, in Simandl, G.J., and Neetz, M., eds., Symposium on Strategic and Critical Materials Proceedings, November 13-14, 2015, Victoria, British Columbia, British Columbia Ministry of Energy and Mines, British Columbia Geological Survey Paper 2015-3, p. 131-138, http://www.empr.gov.bc.ca/Mining/Geoscience/PublicationsCatalogue/Papers/Documents/P2015-3/16%20Foley.pdf. [PDF file, 2.9 MB]

Foley, N.K., and Ayuso, R.A., 2013, Rare earth element mobility in high-alumina altered metavolcanic deposits, South Carolina, USA: Journal of Geochemical Exploration, 133, p. 50-67, doi:10.1016/j.gexplo.2013.03.008.

Foley, N.K., and Ayuso, R.A., 2012, Gold deposits of the Carolina Slate Belt, southeastern United States—Age and origin of the major gold producers: U.S. Geological Survey Open-File Report 2012–1179, 26 p., http://pubs.usgs.gov/of/2012/1179/.

Foley, N.K., and Ayuso, R.A., 2008, Mineral sources and transport pathways for arsenic release in a coastal watershed, USA: Geochemistry: Exploration, Environment, Analysis, 8(1), p. 59-75, doi:10.1144/1467-7873/07-152.

Foley, N.K., Ayuso, R.A., Ayotte, J.D., Montgomery, D.L., and Robinson, G.R., Jr., 2007, Geological assessment of cores from the Great Bay National Wildlife Refuge, New Hampshire: U.S. Geological Survey Scientific Investigations Report 2006–5203, 62 p., http://pubs.usgs.gov/sir/2006/5203/.

Foley, N.K., Ayuso, R.A., Bern, C.R., Hubbard, B.E., and Vazquez, J.A., 2014, REE distribution and mobility in regolith formed on granite bedrock of the southeast United States: Acta Geologica Sinica (English Edition), 88(s2), p. 428-430, doi:10.1111/1755-6724.12373_8.

Foley, N.K., Ayuso, R.A., and Seal, R.R., 2001, Remnant colloform pyrite at the Haile gold deposit, South Carolina: A textural key to genesis: Economic Geology, 96(4), p. 891-902, http://dx.doi.org/10.2113/gsecongeo.96.4.891.

Gilg, H.A., Lima, A., Somma, R., Belkin, H.E., De Vivo, B., and Ayuso, R.A., 2001, Isotope geochemistry and fluid inclusion study of skarns from Vesuvius: Mineralogy and Petrology, 73(1), p. 145-176, http://dx.doi.org/10.1007/s007100170015.

Grezzi, G., Ayuso, R.A., De Vivo, B., Lima, A., and Albanese, S., 2011, Lead isotopes in soils and groundwaters as tracers of the impact of human activities on the surface environment: The Domizio-Flegreo Littoral (Italy) case study: Journal of Geochemical Exploration, 109(1-3), p. 51-58, doi:10.1016/j.gexplo.2010.09.012.

Kelley, K.D., Leach, D.L., Johnson, C.A., Clark, J.L., Fayek, M., Slack, J.F., Anderson,V.M., Ayuso, R.A., and Ridley, W.I., 2004, Textural, Compositional, and Sulfur Isotope Variations of Sulfide Minerals in the Red Dog Zn-Pb-Ag Deposits, Brooks Range, Alaska: Implications for Ore Formation: Economic Geology, 99(7), p. 1509-1532, doi:10.2113/gsecongeo.99.7.1509.

Lipfert, G., Sidle, W.C., Reeve, A.S., Ayuso, R.A., and Boyce, A.J., 2007, High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system: Chemical Geology, 242(3-4), p. 385-399, doi:10.1016/j.chemgeo.2007.04.003.

Lima, A., Giaccio, L., Cicchella, D., Albanese, S., Bove, M., Grezzi, G., Ayuso, R.A., and De Vivo, B., 2011, Atlante geochimico-ambientale del S.I.N. (Sito di interese nazionale) Litorale domizio-flegreao e agro aversano—Geochemical Environmental Atlas of Sito di Interesse Nazionale, Domizio-Flegreo Littoral and Agro Aversano: University of Naples Publications, Naples, Italy, 258 p., http://www.aracneeditrice.it/aracneweb/index.php/pubblicazione.html?item=9788854851481.

Martiny, B., Martı́nez-Serrano, R.G., Morán-Zenteno, D.J., Macı́as-Romo, C., and Ayuso, R.A., 2000, Stratigraphy, geochemistry and tectonic significance of the Oligocene magmatic rocks of western Oaxaca, southern Mexico: Tectonophysics, 318(1-4), p. 71-98, http://dx.doi.org/10.1016/S0040-1951(99)00307-8.

Paone, A., Ayuso, R.A., and De Vivo, B., 2001, A metallogenic survey of alkalic rocks of Mt. Somma-Vesuvius volcano: Mineralogy and Petrology, 73(1), p. 201-233, http://dx.doi.org/10.1007/s007100170017.

Schulz, K.J., and Ayuso, R.A., 2003, Lithogeochemistry and Paleotectonic Setting of the Bald Mountain Massive Sulfide Deposit, Northern Maine, in Goodfellow, W.D., et al., eds., Volcanogenic massive sulfide deposits of the Bathurst district and northern Maine: Economic Geology Monograph 11, p. 79-109. View Schulz and Ayuso abstract.

Seal, R.R., and Ayuso, R.A., 2011, Understanding processes affecting mineral deposits in humid environments: U.S. Geological Survey Fact Sheet 2010–3105, 6 p., http://pubs.usgs.gov/fs/2010/3105/.

Seal, R.R., II, Ayuso, R.A., Foley, N.K., and Clark, S.H.B., 2001, Sulfur and lead isotope geochemistry of hypogene mineralization at the Barite Hill gold deposit, Carolina slate belt, southeastern United States: a window into and through regional metamorphism: Mineralium Deposita, 36(2), p. 137-148, doi:10.1007/s001260050294.

Seal, R.R., II, Hammarstrom, J.M., Johnson, A.N., Piatak, N.M., and Wandless, G.A., 2008, Environmental geochemistry of a Kuroko-type massive sulfide deposit at the abandoned Valzinco mine, Virginia, USA: Applied Geochemistry, 23(2), p. 320-342, doi:10.1016/j.apgeochem.2007.10.001.

Seal, R.R., II, and Shanks, W.C., III, 2008, Sulfide oxidation: Insights from experimental, theoretical, stable isotope, and predictive studies in the field and laboratory: Applied Geochemistry, 23(2), p. 101-102, doi:10.1016/j.apgeochem.2007.10.006.

Shawe, D.R., Hoffman, J.D., Doe, B.R., Foord, E.E., Stein, H.J., and Ayuso, R.A., 2003, Geochemistry, geochronology, mineralogy, and geology suggest sources of and controls on mineral systems in the southern Toquima Range, Nye County, Nevada; with geochemistry maps of gold, silver, mercury, arsenic, antimony, zinc, copper, lead, molybdenum, bismuth, iron, titanium, vanadium, cobalt, beryllium, boron, fluorine, and sulfur; and with a section on lead associations, mineralogy and paragenesis, and isotopes: U.S. Geological Survey Miscellaneous Field Studies Map 2327-C, 5 sheets accompanied by 65 page text, http://pubs.usgs.gov/mf/2003/mf-2327-c/.

Tappa, M.J., Ayuso, R.A., Bodnar, R.J., Aylor, J.G., Beard, J., Henika, W.S., Vazquez, J.A., and Wooden, J., 2014, Age of host rocks at the Coles Hill uranium deposit, Pittsylvania County, Virginia, USA, based on zircon U-Pb geochronology: Economic Geology, 109(2), p. 513-530, doi:10.2113/econgeo.109.2.513.

Till, A.B., Dumoulin, J.A., Ayuso, R.A., Aleinikoff, J.N., Amato, J.M., Slack, J.F., and Shanks, W.C., III, 2014, Reconstruction of an early Paleozoic continental margin based on the nature of protoliths in the Nome Complex, Seward Peninsula, Alaska: Geological Society of America, Special Papers 506, p. 1-28, doi:10.1130/2014.2506(01)​.

Publications of Previous Research

Arth, J.G., and Ayuso, R.A., 1997, The Northeast Kingdom Batholith, Vermont: Geochronology and Nd, O, Pb, and Sr isotopic constraints on the origin of Acadian granitic rocks, in Sinha, A.K., Whalen, J.B., and Hogan, J.P., eds., The Nature of Magmatism in the Appalachian Orogen: Geological Society of America, Memoirs 191, p. 1-18, doi:10.1130/0-8137-1191-6.1.

Ayuso, R.A., 1999, Geochemical and metallogenic contrasts in Paleozoic granitic rocks of the northern New England Appalachians, in Ludman, A., and West, D.P., Jr., eds., Norumbega Fault System of the Northern Appalachians: Geological Society of America Special Papers 331, p. 121-154, doi:10.1130/0-8137-2331-0.121.

Ayuso, R.A., 1998, Radiogenic isotopes and the Eastern Mineral Resources Program of the U.S. Geological Survey: U.S. Geological Survey Information Handout, 4 p., http://pubs.usgs.gov/info/ayuso2/.

Ayuso, R.A., 1998, Carolina slate belt gold deposits in Virginia, North Carolina, South Carolina, and Georgia: U.S. Geological Survey Information Handout, 2 p., http://pubs.usgs.gov/info/ayuso1/.

Ayuso, R.A., and Arth, J.G., 1997, The Spruce Head composite pluton: An example of mafic to silicic Salinian magmatism in coastal Maine, northern Appalachians, in Sinha, A.K., Whalen, J.B., and Hogan, J.P., eds., The Nature of Magmatism in the Appalachian Orogen: Geological Society of America, Memoirs 191, p. 19-43, doi:10.1130/0-8137-1191-6.19.

Ayuso, R.A., Callender, E., and Van Metre, P., 2001, Pb isotopes of lake sediments and effects of human activities on water quality, in Cidu, R., ed., Proceedings of the Tenth International Symposium on Water Rock Interaction, 2, Balkema, p. 1473-1475.

Ayuso, R.A., De Vivo, B., Rolandi, G., Seal, R.R., II, and Paone, A., 1998, Geochemical and isotopic (Nd-Pb-Sr-O) variations bearing on the genesis of volcanic rocks from Vesuvius, Italy: Journal of Volcanology and Geothermal Research, 82(1-4), p. 53-78, doi:10.1016/S0377-0273(97)00057-7.

Carmody, R.W., and Seal, R.R., II, 1999, Evaluation of the sulfur isotopic composition and homogeneity of the Soufre de Lacq reference material: Chemical Geology, 153(1-4), p. 289-295, http://dx.doi.org/10.1016/S0009-2541(98)00159-4.

Seal, R.R., II, and Shanks, W.C., III, 1998, Oxygen and hydrogen isotope systematics of Lake Baikal, Siberia: Implications for paleoclimate studies: Limnology and Oceanography, 43(6), p. 1251-1261, doi:10.4319/lo.1998.43.6.1251.

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Abstracts for Presentations and Posters

Ayuso, R.A., Callender, E., and Van Metre, P., 2001, Pb isotopes of lake sediments and effects of human activities on water quality, in Cidu, R., ed., Proceedings of the Tenth International Symposium on Water Rock Interaction, 2, Balkema, p. 1473-1475.

Ayuso, R., De Vivo, B., Piocci, M., and Somma, R., 2004, Diverse magma sources and crustal contamination processes at Mt. Somma-Vesuvius, Italy: geochemical and Sr-isotopical evidence: International Geological Congress, Florence, August 20-28, 2004, Abstract Volume 1, p. 511, session 106.

Ayuso, R.A., and Foley, N.K., 2016, Prospective Source Rocks and Accumulation Processes for Deposits of the REE Ion Adsorption Clay-Type, Southeastern United States: Goldschmidt Abstracts, 2016 558. View Ayuso 2016 Goldschmidt abstract.

Ayuso, R.A., Foley, N.K., Ayotte, J.D., Lyon, A., Burns, J., Marvinney, R.G., Reeve, A., and Robinson, G., 2002, Pb isotopes, arsenic sources and enrichment pathways linking sulfides from mines and unmineralized rocks to secondary iron oxides, coastal New England: Arsenic in New England: A multidisciplinary Scientific Conference 2002, New Hampshire Consortium on Arsenic, Program with abstracts, p. 29.

Ayuso, R.A., and Kelley, K.D., 2007, Tracing metal sources of Zn-Pb-Ag deposits in the Brooks Range, Alaska: Pb-Sr-Nd isotope constraints: The 23rd International Applied Geochemistry Symposium (IAGS 2007), Oviedo, Spain, 14-19 June, p. 110.

Ayuso, R.A., Piochi, M., De Vivo, B., and Somma, R., 2005, Crustal contamination and crystal entrapment in volcanic rocks from Mt. Somma-Vesuvius volcano, Italy: Geochemical and Sr isotope Evidence: in International Workshop on Vesuvius and Volcanism of the Campanian Plain, southern Italy, Naples, Oct. 4-6, 2004, DeVivo, B., ed., p. 11-12.

Ayuso, R.A., and Till, A.B., 2007, Geochemical and Nd-Pb isotopic evolution of metabasites from attenuated continental lithosphere, Nome Group, Seward Peninsula, Alaska: Geological Society of America Abstracts with Programs, Vol. 39, No. 6, p. 489. View Ayuso 2007 GSA abstract.

Foley, N.K., Ayuso, R.A., Ayotte, J., Marvinney, R., Reeve, A., and Robinson, G., 2002, Mineralogical pathways for arsenic in weathering of metashales: an analysis of regional and site studies in the northern Appalachians: Arsenic in New England, a multidisciplinary scientific conference 2002, New Hampshire Consortium on Arsenic, Program with abstracts, p. 35.

Foley, N.K., Ayuso, R.A., and Seal, R.R. II, 2007, Gold deposits in the Avalonian tectonic zone of the Southeastern United States, in Andrew, C.J., and others (eds.), Digging Deeper, Proceedings of the Ninth Biennial SGA Meeting, Dublin, Ireland, v. 2, p. 375-377. View Foley SGA 2007 abstract.

Foley, N.K., Bern, C.R., Ayuso, R.A., Hubbard, B.E., and Shah, A.K., 2015, Geochemical and mineralogical characteristics of REE in granite-derived regolith: a model for the Southeast United States, in Mineral Resources In A Sustainable World - The Society for Geology Applied to Mineral Deposits (SGA), 13th Biennial Meeting 2015, Nancy, France, Proceedings, Volume 2, p. 725-728.

Goldfarb, R., Ayuso, R., Miller, M., Ebert, Marsh, E., Petsel, S., and Miller, L., 2004, Metallogeny of the superlarge Donlin Creek gold deposit, southwestern Alaska: International Geological Congress, Florence, August 20-28, 2004, Abstract Volume 1, p. 655, session 143.

Karl, S.M., Ayuso, R.A., Slack, J.F., and Haeussler, P.J., 2007, Evolution of the Alexander terrane oceanic arc, southeast Alaska, reflected in Proterozoic to Triassic rift-associated VMS deposits: Arizona Geological Society meeting, Tucson, AZ.

Ludington, S., Ayuso, R.A., Hammarstrom, J.M., Zientek, M.L., and Qiu, R., 2011, Non-subduction porphyry copper deposits: a comparison between Asia and North America: 11th SGA Biennial Meeting, p. 31-33. Abstract online at http://e-sga.org/shop/product-details/?categories_id%5B0%5D=31&categories_id%5B1%5D=45&products_id=2100&tx_multishop_pi1%5Bpage_section%5D=products_detail.

Raia, F., Ayuso, R.A., DeVivo, B., and Somma, R., 2007, Nd-Sr-Pb Isotopic Link Between Panarea And Sardinia Predating The Opening Of The Tyrrhenian Sea: Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract V13D-1589. View Raia 2007 AGU abstract.

Reeve, A., Horesh, M., Marvinney, R., and Ayuso, R.A., 2002, Arsenic geochemistry in a bedrock aquifer, Northport, Maine: Arsenic in New England, a multidisciplinary scientific conference 2002, New Hampshire Consortium on Arsenic, Program with abstracts, p. 20.

Robinson, G.R., Jr., Ayotte, J.D., and Ayuso, R.A., 2000, Arsenic in Bedrock, Ground Water, and Soils in New England: Eos Trans. AGU, 81(48), Fall Meet. Suppl., Abstract H21D-06. View Robinson 2000 AGU abstract.

Slack, J.F., Till, A.B., Ayuso, R.A., Shanks, W.C., III, Dumoulin, J.A., Amato, J.M., Aleinikoff, J.N., and Bleick, H.A., 2008, SEDEX Zn-Pb-Ag-Au deposits of the Paleozoic Nome Group, southwestern Seward Peninsula, Alaska: Roundup 2008 Conference, January 27-31, 2008, Vancouver, B.C., Canada, Poster Session, Association for Mineral Exploration British Columbia.

Somma, R., Ayuso, R.A., and De Vivo, B., 2000, Geochemical and Sr isotopic evolution of plinian and interplinian rocks from Mt. Somma-Vesuvius (Southern Italy): American Geophysical Union, v. 81, S440. View Somma 2007 AGU abstract.

Somma, R., Belkin, H.E., Ayuso, R.A., and De Vivo, B., 2000, Geochemical and Isotopic Evolution of Panarea Island: The Oldest Volcano in the Aeolian Arc: Eos Trans. AGU, 81(48), Fall Meet. Suppl., Abstract V52F-04. View Somma 2000 AGU abstract.

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Project Contacts

Project Chief

Robert Ayuso
Phone: 703-648-6347
Email: rayuso@usgs.gov
Eastern Mineral and Environmental Resources Science Center

Other Project Members

Robert Seal, rseal@usgs.gov
Sayon Robinson, srobinson@usgs.gov

Mineral Resources Program Science Priority

The use of firm, trade, and brand names is for identification purposes only and does not constitute endorsement by the U.S. government.

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