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Overview

USGS LA-ICPMS laboratory
USGS laser ablation inductively coupled plasma mass spectrometer (LA-ICPMS) in Denver, CO.

A new double-focusing single-collector inductively coupled plasma mass spectrometer (SC-ICPMS) at USGS has the ability to perform rapid in situ isotopic analyses of geological materials by laser ablation (LA). This laser ablation single-collector inductively coupled plasma mass spectrometer (LA-SC-ICPMS) is ideally suited for geochronological and isotopic tracer studies related to the timing, duration, and rates of mineralization and the sources of ore-forming fluids. Several ongoing Mineral Resources Program projects rely on geochronology (e.g., uranium-lead (U-Pb) dating of zircon), and most of these studies would also benefit from lead and strontium isotopic data on the mineral scale. We anticipate that the ability to obtain precise and accurate in situ age and isotopic tracer information for USGS minerals-related projects will continue to be vitally important in the future.

Our LA-SC-ICPMS has the capability of providing cost-effective in situ geochronological and mineral isotope tracer data, but the analytical techniques need to be developed further to reach their full potential. Our facility and research scientists are well-positioned to open exciting new frontiers related to in situ geochronology and mineral isotope tracer research, and these new avenues of research will be fully available to the USGS research.

The primary goal of this project is to improve the precision and accuracy of routine uranium-lead dating of zircon, expanding our LA-SC-ICPMS dating technique to other uranium-rich minerals (e.g., monazite, apatite, xenotime), and developing novel LA-ICPMS in situ lead and strontium isotopic tracer methods applicable to studies of ore mineralization and the framework geology of Mineral Resources Program research study areas. The development of the most precise geochronologic and novel isotope tracer methods would open new avenues for minerals-related research including, for example, geochronology of monazite, apatite, and titanite and lead-isotope studies of ore-related feldspar.

Project Activities

Instrumentation

  • Double-focusing mass spectrometer with low noise discrete dynode electron multiplier detector
    • Beam attenuation capacity (~ factor of 500 reduction)
    • Faraday for larger dynamic range (~1012)
  • Continuiously variable high resolution capabilities
    • From 300 to > 10,000 (10% valley definition)
  • Fast electrostatic scanning / jumping
    • Up to 40% of the mass range
    • No mass discrimination effects
  • Fully laminated, large radius magnet
    • High scan speed - m/z 6 to 250 in < 220 ms

Uranium-Lead (U-Pb) Geochronology

  • High precision and spatial resolution uranium-lead dating of zircon and other uranium-enriched minerals
    • Precise and accurate age determination of high-uranium and -thorium zircon (>2000 ppm) with no apparent matrix effects
    • Uranium-Lead geochronology of monazite micro-inclusions
    • Precise Uranium-Lead geochronology of sub-25┬Ám across zircon
U-Pb dating of zircon
Age determination of zircon sample. Photo by USGS.

Lead-isotope Studies

  • In situ Pb-isotope ratio determination of feldspar, pyrite, and glass materials
    • Precision and accuracy within accepted values of natural and reference materials in both raster and spot mode
    • Determination of Pb-isotope ratios of individual grains of eolian potassium feldspar from Greeley dune field (NE CO)-LA-ICPMS vs bulk TIMS analysis
    • Pb-isotope ratios for pyrites from the Pea Ridge iron oxide-apatite deposit directly measured by LA-ICPMS
apatite and pyrite sample being analyzed
In situ U-Pb dating of apatite and Pb-isotope analysis of co-existing pyrite. Photo by USGS.

Publications

Keller, S.M., Hagadorn, J.W., Morgan, M.L., Whiteley, K.R., Lahey, B.L., Henderson, C.M., and Holm-Denoma, C.S., 2016, The Permian-Triassic transition in Colorado: Geological Society of America Field Guide 44, p. 73-92. View Keller Chapter.

Neymark, L.A., Holm-Denoma, C.S., Pietruszka, A.J., Aleinikoff, J.N., Fanning, C.M., Pillers, R.M., and Moscati, R.J., 2016, High Spatial Resolution U-Pb Geochronology and Pb Isotope Geochemistry of Magnetite-Apatite Ore from the Pea Ridge Iron Oxide-Apatite Deposit, St. Francois Mountains, Southeast Missouri, USA: Economic Geology, 111(8), p. 1915-1933, doi:10.2113/econgeo.111.8.1915.

Pietruszka, A.J., and Neymark, L.A., 2017, Evaluation of laser ablation double-focusing SC-ICPMS for "common" lead isotopic measurements in silicate glasses and minerals: Journal of Analytical Atomic Spectrometry, 32(6), p. 1135-1154, doi:10.1039/c7ja00005g.

Abstracts for Posters and Presentations

Charts shoping lead and lead-uranium isotopic data
Dating apatite from Pea Ridge iron oxide-apatite deposit, southeast Missouri. Presented by Neymark and others at Goldschmidt 2015 conference. View Neymark Goldschmidt abstract. Image by USGS.

Aleinikoff, J., Neymark, L., Selby, D., Day, W., Slack, J., Holm-Denoma, C., Pillers, R., Seeger, C., and Samson, I., 2015, U-Pb and Re-Os Geochronology of REE-Rich Breccia Pipes and Magnetite Ore from the Mesoproterozoic Pea Ridge Fe-REE-Au Deposit, St. Francois Mountains, Missouri, USA: Society of Economic Geologists 2015 Annual Meeting, September 27-30, 2015, Hobart, TAS, Australia. View Aleinikoff SEG abstract. [PDF file, 36 kb]

Bala, S.A., Holm-Denoma, C.S., Neymark, L.A., Taylor, C.D., Pietruszka, A.J., and Driscoll, R.L., 2014, U-Pb zircon ages and mineralogy of the Dora Bay instrusive complex and heavy REE-bearing pegmatite dikes: Geological Society of America Abstracts with Programs, Vol. 46, No. 6, p. 782. View Bala 2014 GSA abstract.

Balogh, C., Holm-Denoma, C., and Vikre, P.G., 2016, Volcanic stratigraphy, hydrothermal alteration and telluride-bearing epithermal deposits of the Patterson mining district, Sweetwater Mountains, CA-NV: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-285486.

Barineau, C.I., Tull, J.F., and Holm-Denoma, C.S., 2015, Ordovician events in the southern Appalachians: Synthesizing the igneous, sedimentary and metamorphic record of the Taconic orogeny: Geological Society of America Abstracts with Programs, Vol. 47, No. 2, p. 22. View Barineau 2015 Southeast Section GSA abstract.

Barineau, C.I., Tull, J.F., Mueller, P.A., Sagul, D.A., and Holm-Denoma, C.S., 2015, Tectonic implications of Ordovician-Silurian magmatic-volcanic sequences in the eastern Blue Ridge and inner Piedmont, southern Appalachian orogen: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 863. View Barineau 2015 GSA abstract.

Hagadorn, J.W., Bullecks, J., Soar, L.K., Lahey, B.L., Over, D.J., Wistort, Z.P., and Holm-Denoma, C.S., 2016, Colorado mass extinction: weird facies and cool fossils from the end-Devonian Dyer Formation: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-287728.

Hagadorn, J.W., and Holm-Denoma, C.S., 2016, Linking Neoproterozoic to Cambrian strata from Sonora to Utah: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-287769.

Hagadorn, J.W., Whiteley, K.R., Lahey, B.L., Holm-Denoma, C.S., and Henderson, C.M., 2016, The Permian-Triassic of eastern Colorado: redbeds, slime, salt, dunes, and possibly an extinction?: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-287701.

Holm-Denoma, C.S., Carter, M.W., Burton, W.C., Evans, N.H., and Spears, D.B., 2016, U-Pb detrital zircon geochronology of terranes in the central Virginia Piedmont: Geological Society of America Abstracts with Programs, Vol. 48, No. 3, doi:10.1130/abs/2016SE-273672.

Holm-Denoma, C.S., Hagadorn, J.W., Raynolds, R.G., and Neymark, L.A., 2016, One if by land, two if by sea, and three if by air? Sediment transport into Colorado Basins: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-280822.

Holm-Denoma, C.S., and Jones, J.V., III, 2016, Detrital zircon lineages in the allochthonous Yukon-Tanana terrane and parautochthonous North American basement, eastern Alaska and western Yukon: Geologic Association of Canada - Mineralogical Association of Canada (GAC-MAC) 2016 Meeting, June 1-3, 2016, Whitehorse, YT. View Holm-Denoma GAC-MAC abstract.

Holm-Denoma, C.S., McClellan, E., and Southworth, S., 2014, Three episodes of volcanism and erosion during Neoproterozoic extension in eastern Laurentia revealed by U-Pb dating of zircon from clasts of rhyolite and detrital zircon from sedimentary rocks of the Mount Rogers Formation, southwest Virginia: Geological Society of America Abstracts with Programs, Vol. 46, No. 6, p. 90. View Holm-Denoma 2014 GSA abstract.

Holm-Denoma, C.S., Southworth, C.S., Merschat, A.J., and McClellan, E., 2015, The detrital record of Neoproterozoic to Cambrian rocks from the southern Appalachian Blue Ridge: Protracted rifting, rapid unroofing, and stabilization of the margin: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 859. View Holm-Denoma 2015 GSA abstract.

Jones, J.V., III, Caine, J.S., Holm-Denoma, C.S., Lease, R.O., Saltus, R.W., and Todd, E., 2015, Refining the characteristics, age, and extent of the Permian Klondike assemblage in eastern Alaska: Geological Society of America Abstracts with Programs, Vol. 47, No. 4, p. 18. View Jones 2015 Cordilleran Section GSA abstract.

Jones, J.V., III, Holm-Denoma, C.S., and Todd, E., 2016, Lithotectonic associations of the Ladue River unit and implications for the structure of the Yukon-Tanana terrane boundary in eastern Alaska: Geologic Association of Canada - Mineralogical Association of Canada (GAC-MAC) 2016 Meeting, June 1-3, 2016, Whitehorse, YT. View Jones GAC-MAC abstract.

Jones, J.V., III, Holm-Denoma, C.S., and O'Sullivan, P.B., 2015, Using detrital zircon to correlate and reconstruct Neoproterozoic and early Paleozoic components of peri-Laurentian terranes in the northern Cordillera and Alaska: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 860. View Jones 2015 GSA abstract.

Karl, S.M., Box, S.E., Lease, R.O., Jones III, J.V., Holm-Denoma, C.S., Bradley, D.C., and Haeussler, P.J., 2016, Indepedent Jurassic to Late Cretaceous depositional systems defined by sandstone petrography and detrital zircons constrain closure of the Kahiltna-Kuskokwim Basin in southern and southwestern Alaska: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-281104.

Karl, S.M., Box, S.E., Lease, R.O., Jones III, J.V., Holm-Denoma, C., Bradley, D., and Haeussler, P.J., 2015, Formation of the Kahiltna Basin, Alaska, by time-transgressive Early to Late Cretaceous dextral-oblique juxtaposition of two independent depositional systems: Geological Society of America Abstracts with Programs, Vol. 47, No. 4, p. 53. View Karl GSA abstract.

McClellan, E., and Holm-Denoma, C.S., 2014, Neoproterozoic geologic history of eastern Laurentia: Evidence from U-Pb dating of zircon from rhyolite clasts in Mount Rogers Formation conglomerates, SW VA, USA: Geological Society of America Abstracts with Programs, Vol. 46, No. 6, p. 89. View McClellan 2014 GSA abstract.

McClellan, E., Holm-Denoma, C.S., Gazel, E., Risso, B.R., and Brown, E., 2015, Breaking up Rodinia: Magmatic and sedimentological evidence for a mantle plume trigger: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 859. View McClellan 2015 GSA abstract.

McLaughlin, R.J., Colgan, J.P., Elder, W.P., Enderlin, D.A., Dumitru, T.A., Holm-Denoma, C., and Moring, B.C., 2016, Maximum depositional ages and provenance from detrital zircons compared to paleontologic ages and implications for deformation timing, lower Great Valley Sequence, Knoxville to Lake Berryessa, west of Sacramento Valley, CA: Geological Society of America Abstracts with Programs, Vol. 48, No. 4, doi:10.1130/abs/2016CD-274241.

Merschat, A.J., Walsh, G.J., Holm-Denoma, C.S., and McAleer, R.J., 2016, Detrital zircon geochronology of the Bronson Hill anticlinorium and western facies of the central Maine terrane, southern NH-VT: Geological Society of America Abstracts with Programs, Vol. 48, No. 2, doi:10.1130/abs/2016NE-272887.

Merschat, A.J., Holm-Denoma, C.S., Southworth, S., and Mundil, R., 2015, Late Pre-Cambrian continental rifting in the southern Blue Ridge, VA-NC-TN, revisited: Honoring 50 years of Doug Rankin's contributions to Appalachian geology: Geological Society of America Abstracts with Programs, Vol. 47, No. 3, p. 61. View Merschat 2015 Northeast Section GSA abstract.

Merschat, A.J., Southworth, S., Rankin, D.W., Holm-Denoma, C.S., Tollo, R.P., and Aleinikoff, J.N., 2015, Preliminary geologic map of the Mount Rogers area, VA-NC-TN: Field relationships of Neoproterozoic volcanism and glaciation in the Blue Ridge: Geological Society of America Abstracts with Programs, Vol. 47, No. 7, p. 121. View Merschat 2015 GSA abstract.

Neymark, L., Aleinikoff, J., Holm-Denoma, C., Pietruszka, A., Pillers, R., and Moscati, R., 2015, High Spatial Resolution SHRIMP and LA-ICPMS U-Pb Geochronology of Pea Ridge Fe-Ree-Au Deposit, USA: Goldschmidt Abstracts, 2015 2264. View Neymark Goldschmidt abstract.

Neymark, L.A., Holm-Denoma, C., Pietruszka, A.J., Meighan, C.J., and Moscati, R.J., 2016, In situe LA-ICPMS U-Pb geochronology of apatite from IOA and IOCG deposits, St. Francois Mountains, southeast Missouri, USA: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-279719.

Pietruszka, A.J., and Neymark, L.A., 2016, Potential limits on the accuracy of Pb isotopic measurements by LA-ICPMS due to matrix effects: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-280329.

Pietruszka, A., and Neymark, L., 2014, Methods Development for In Situ Laser-Ablation Pb and Sr Isotopic Analyses Using a Double-Focusing Single-Collector ICPMS: American Geophysical Union Fall Meeting, 15-19 December 2014, San Francisco, CA. View Pietruszka AGU abstract.

Premo, W.R., Miller, D.M., Moscati, R.J., Holm-Denoma, C.S., Neymark, L.A., and Ponce, D.A., 2016, Searching for the aerial extent of the Mountain Pass carbonatite event: evidence from U-Pb zircon geochronology of Proterozoic rocks in southwestern United States: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-285949.

Reusch, D.N., Holm-Denoma, C.S., and Slack. J.F., 2016, New U/Pb zircon ages from north Islesboro, western Penobscot Bay, Maine: Stratigraphic and tectonic implications: Geological Society of America Abstracts with Programs, Vol. 48, No. 2, doi:10.1130/abs/2016NE-272025.

Taylor, C.D., Aleinikoff, J.N., Holm-Denoma, C.S., Neymark, L.A., Bala, S.A., Pascarelli, S.E., Pillers, R.M., Karl, S.M., Van Gosen, B.S., Morgan, L.E., and Cosca, M.A., 2016, New geochronologic constraints on the formation and hydrothermal enrichment of the Bokan Mountain peralkaline igneous complex and associated HREE deposits, southeastern Alaska, USA: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-286288.

Tull, J.F., Barineau, C.I., Holm-Denoma, C., Farris, D.W., Mueller, P.A., and Davis, B.L., 2016, Remnants of a paired Laurentian taconic arc/back-arc system in the southernmost Appalachians?: Geological Society of America Abstracts with Programs, Vol. 48, No. 3, doi:10.1130/abs/2016SE-273376.

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