Crustal Geophysics and Geochemistry Science Center

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Isotope Geochemistry/Geochronology Research and Development - Multiuser New Capabilities

Project Objectives

This project represents the research and development component of the Core Operations project. The isotope geochemistry/geochronology laboratories are critical to the scientific health of Geologic Discipline as well as Bureau Programs, are a venue for developing future multi-disciplinary research, and with full scientific participation in projects, is a cost effective source for projects across virtually all Geologic Discipline programs. To maintain a future looking scientific research and development effort within Isotope and Geochronologic Geochemistry, periodic new and continuing research and development efforts are proposed. These tasks all are small efforts, generally not of full project magnitude, require nominal investment for potentially significant future returns to Programs, Geologic Discipline and to the Bureau, expand our capabilities and skills, and enable the Bureau to be responsive to new and anticipated future opportunities with the necessary skill base and laboratory infrastructure.

Core Operations research and development is an important component of task(s) that require programs' investment to enable new, improved, or redirected research methods and and to allow exploratory and normally collaborative research into new (multidisciplinary) fields. These efforts cannot be supported at the project level, require funding of time and expenses, and are critical to developing new opportunities and preparing for the future. Facilities/capabilities for which research and development tasks might be considered include: a) radiogenic isotopes: the TIMS solid source mass spectrometer bay for U-Th-Pb, U-series, Rb-Sr, Nd-Sm, Lu-Hf; b) stable isotopes: carbon, oxygen, nitrogen, hydrogen, and sulfur isotope systematics; c) argon geochronology: both K-Ar and 40Ar/39Ar from several thousand years to oldest Archean age using both conventional and laser fusion techniques; d) noble gas geochemistry: groundwater tracer applications and tritium-3He age, cosmogenic exposure age (3He and 21Ne), U-Th-4He geochronology, and volcanic, geothermal, and fluid inclusion noble gas geochemistry of mineral deposits; and e) thermoluminescence-optically stimulated luminescence (TL/OSL). These research and development tasks extend useful capabilities and expand opportunities to numerous Geologic Discipline programs and the Bureau.

Relevance & Impact

The various tasks of this project as research and development efforts hold potential for refining existing methods in argon geochronology, and providing better definitions and calibration of reference standards, developing new methods of dating the age of deposition of sedimentary rocks by dating diagenetic xenotime overgrowths on detrital zircons, and developing new sampling methods for tracer studies in groundwater that will enhance the ability of data generated to be related to subsurface geologic features. These research and development tasks within this project will strengthen the abilities of Geologic Discipline programs to achieve stated scientific goals by developing or enhancing skills and capabilities of the scientific staff and facilities.

Project Chief:

Gary Landis Box 25046 MS 963
Denver, CO 80225
(303) 236-2452
glandis@usgs.gov

Products

Products are listed according to task:

Tasks Title
Task 1 Research and Development of a Breakthrough Method for Dating Sedimentary Sequences: U-Pb SHRIMP Dating of Diagenetic Xenotime
Task 2 Calibration of MMhb-2, the Argon Standard
Task 3 Application of high resolution argon thermochronology to difficult problems
Task 4 Noble gas tracers in magmatic and meteoric groundwater/surface water/fluid inclusion gases - natural tracers of mineralizing fluids in ore-forming environments

Task 1 - Research and Development of a Breakthrough Method for Dating Sedimentary Sequences: U-Pb SHRIMP Dating of Diagenetic Xenotime

Workshops

  • Fletcher, I., McNaughton, N., Rasmussen, B., and Aleinikoff, J.N., Pb/U and Pb/Th analyses of xenotime: standards, calibrations, and matrix effects: SHRIMP users workshop, Australian National University, Murramurang, Australia, p. 32.

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Task 2 - Calibration of MMhb-2, the Argon Standard

Presentations

  • Kunk, M.J., and Miiller, A.P., 2002, Completion of NIST calibration of argon spikes, and plans for interlaboratory calibration of MMhb-2: Geological Society of America Abstracts with Programs, vol.34, no. 6, p. 340. View Kunk GSA abstract.

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Task 3 - Application of high resolution argon thermochronology to difficult problems

Posters

  • Snee, L.W., Vielreicher, Noreen, and Baggott, Matthew, 2003, Australian Archean Argon--Does it Work?: Geological Society of America Abstracts with Programs, vol. 35, no. 6, p. 235. View Snee GSA abstract.

Reports

  • Harlan, S.S., Snee, L.W., Reynolds, M.W., Mehnert, H.H., Schmidt, R.G., Sheriff, S.D., Irving, A.J., 40Ar/39Ar and K-Ar geochronology and tectonic significance of the Upper Cretaceous Adel Mountain volcanics and spatially associated Tertiary igneous rocks, northwestern Montana: U.S. Geological Survey Professional Paper 1696, 33 p.
  • Juiliani, C., Rye, R.O., Nunes, C.M.D., Snee, L.W., Silva, R.H., Monteiro, L.V.S., Bettencourt, J.S., Neumann, R., and Neto, A.A., 2005, Paleoproterozoic high-sulfidation mineralization in the Tapajos gold province, Amazonian craton, Brazil: Geology, mineralogy, alunite argon age, and stable isotope constraints: Chemical Geology, vol. 215, pp. 95-125.
  • Landis, G.P., Snee, L.W., and Juliani, C., 2005, Evaluation of argon ages and integrity of fluid inclusion compositions: Stepwise noble gas heating experiments on 1.87-Ga alunite from Tapajos Province, Brazil: Chemical Geology, vol. 215, pp. 127-153.
  • Prueher, L.M., Erlich, R., and Snee, L.W., 2005, 40Ar/39Ar geochronology of hpabyssal igneous rocks in the Maranon Basin of Peru - A record of thermal history, structure, and alteration: U.S. Geological Survey Scientific Investigations Report 2005-5132, 41 p.
  • Roeske, S.M., Snee, L.W., and Pavlis, T.L., 2004, Dextral-slip reactivation of an arc-forearc boundary during Late Creataceous-Early Eocene oblique convergence in the northern Cordillera: Geological Society of America Special Paper 371, pp. 141-169.
  • Snee, L.W., 2002, Argon thermochronology of mineral deposit--a review of analytical methods, formulations, and selected applications: U.S. Geological Survey Bulletin 2194, 39 p.

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Task 4 - Noble gas tracers in magmatic and meteoric groundwater/surface water/fluid inclusion gases - natural tracers of mineralizing fluids in ore-forming environments

Presentations

  • Grauch, R.I., Lewan, M.D., Lamothe, P.J., Landis,G.P., and Emsbo, P., 2004, Element partitioning into generated petroleum and hydrothermal fluids as determined by hydrous pyrolysis of Retort Shale: Geological Society of America Abstracts with Programs, vol. 36, no. 5, p. 199. View Grauch GSA abstract.
  • Hunt, A.R., Lambert, R.B., Waugh, J.R., and Landis, G.P., 2003, Fluid logging and discrete sampling of the freshwater/saline-water interface of the Edwards aquifer, south central Texas: Implications for groundwater flow and origin of salinity (Part 2-Geochemistry): Geological Society of America Abstracts with Programs, vol. 35, no. 6, p. 280. View Hunt GSA abstract.
  • Lambert, R.B., Hunt, A.G., Landis, G.P., and Waugh, J.R., 2003, Fluid logging and discrete sampling of the freshwater/saline-water interface of the Edwards aquifer, south central Texas: Implications for groundwater flow and origin of salinity (Part 1-Fluid Logging): Geological Society of America Abstracts with Programs, vol. 35, no. 6, p. 280. View Lambert GSA abstract.
  • Manning, A.H., Caine, J.S., Verplanck, P.L., Bove, D.J., and Landis, G.P., 2004, Insights into groundwater flow in an alpine watershed provided by a coupled heat, mass, and fluid transport model, Handcard Gulch, Colorado: Geological Society of America Abstracts with Programs, vol. 36, no. 5, p. 539. View Manning GSA abstract.

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