James Paces
Primary research responsibilities includes collection of radiogenic isotope data (U-series and Sr) used to date Quaternary deposits and provide natural tracers of mass flow through near-surface environments.
EMPLOYMENT HISTORY
Scientist Emeritus, USGS, Geology and Environmental Change Science Center, (2021-)
Research Geologist, USGS, Geology and Environmental Change Science Center, (2010 - 2020)
Geochronological and radiogenic isotope studies associated with 1) Quaternary landscape evolution for Geologic-Mapping Studies at Buffalo National River, AR; Greater Platte River basin, CO; Rio Grande Rift, NM & CO, 2) probabilistic seismic hazard analyses, eastern WA, 3) Pleistocene water-table fluctuations and aquifer sources at Wind Cave NP, SD, 4) ages of megafauna and archaeological sites, CO & CA, 5) hydrologic sources and mixing in modern and paleohydrologic environments (Pahranagat NWR, NV; Sacramento-San Joaquin Delta, CA; Yellowstone NP, WY; Gallatin Valley, MT; upper Santa Cruz River basin; AZ), 6) structural evolution of Channel Islands NP, CA, 7) timing of U mineralization, TX & VA.
Research Hydrologist, USGS, Yucca Mountain Project Branch, (1992 - 2010)
Geochemical and isotopic characterization of the Nation’s proposed high-level radioactive waste repository at Yucca Mountain, NV. Studies of both surface- and subsurface-based geochronology, hydrology, and paleoclimate investigations using Sr and U-Th isotopes to characterize modern and Pleistocene hydrologic processes.
Geologist, Natl. Res. Council Post-doc, USGS, Branch of Isotope Geology (1990 - 1991)
1) Isotopic (U-Pb, Rb-Sr, Sm-Nd) investigation of lower crustal nodules from Jurassic kimberlites, MI, 2) High-precision, single-zircon U-Pb dating of 1.1 Ga mafic intrusions in the Duluth Complex, MN.
Geologist, Post-doc fellow, Univ. Tennessee (1989)
Sr- and Nd-isotope study of whole rocks and mineral separates of Apollo 17 mare basalts.
EDUCATION
Ph.D. in Geology, Michigan Technological University, Houghton, Michigan, 1988; Magmatic processes, evolution and mantle source characteristics contributing to the petrogenesis of Midcontinent Rift Basalts: Portage Lake Volcanics, Keweenaw Peninsula, MI
B.S. in Geology (with honors), University of Oregon, Eugene, Oregon, 1978
AWARDS
USGS Superior Service Award, 2005
GSA Fellow
Colorado Scientific Society President, 2020
PROFESSIONAL AFFILIATIONS
Geological Society of America
American Geophysical Union
Geochemical Society
International Association of Geochemistry
Science and Products
Filter Total Items: 20
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Filter Total Items: 88
Constraints on Quaternary unsaturated- and saturated-zone hydrology from geochronological and isotopic studies of calcite and silica, Yucca Mountain, Nevada Constraints on Quaternary unsaturated- and saturated-zone hydrology from geochronological and isotopic studies of calcite and silica, Yucca Mountain, Nevada
No abstracts available.
Authors
James Paces, Zell Peterman, Leonid A. Neymark, J. Whelan, Brian Marshall
The climatic and hydrologic history of southern Nevada during the Late Quaternary The climatic and hydrologic history of southern Nevada during the Late Quaternary
No abstract available.
Authors
R. Forester, J.P. Bradbury, C. Carter, A. Elvidge-Tuma, M.L. Hemphill, S.C. Lundstrom, S. A. Mahan, B.D. Marshall, L.A. Neymark, J.B. Paces, S.E. Sharpe, J. Whelan, P.E. Wigand
Late Quaternary history of Fortymile Wash in the area near the H-road crossing Late Quaternary history of Fortymile Wash in the area near the H-road crossing
No abstract available.
Authors
Scott Lundstrom, James Paces, Shannon Mahan
U-Pb age evidence for long-term stability of the unsaturated zone at Yucca Mountain U-Pb age evidence for long-term stability of the unsaturated zone at Yucca Mountain
No abstract available.
Authors
Leonid A. Neymark, Y. Amelin, James Paces, Zell Peterman
Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA
Both unsaturated- and saturated-zone aqueous solutions are capable of precipitating secondary mineral deposits that document the history and origins of past water flux. Calcite and opal occur as thin coatings on open fractures and cavity floors within the thick unsaturated zone at Yucca Mountain. Outermost surfaces of calcite have 14C ages of between 44,000 and 16,000 radiocarbon years...
Authors
James Paces, Zell Peterman, Leonid A. Neymark, Joseph Whelan, Brian Marshall
Secondary minerals record past percolation flux at Yucca Mountain, Nevada Secondary minerals record past percolation flux at Yucca Mountain, Nevada
No abstract available.
Authors
Brian Marshall, James Paces, Leonid A. Neymark, J. Whelan, Zell Peterman
Neogene to Quaternary U-Th-Pb geochronology using opal, Yucca Mountain, Nevada, USA Neogene to Quaternary U-Th-Pb geochronology using opal, Yucca Mountain, Nevada, USA
No abstract available.
Authors
Leonid A. Neymark, James Paces, Yu. Amelin
Inferences for Yucca Mountain unsaturated-zone hydrology from secondary minerals Inferences for Yucca Mountain unsaturated-zone hydrology from secondary minerals
No abstract available.
Authors
James Paces, Leonid A. Neymark, Brian Marshall, J. Whelan, Zell Peterman
Anomalous groundwater 234U/238U beneath Yucca Mountain: Evidence for local recharge? Anomalous groundwater 234U/238U beneath Yucca Mountain: Evidence for local recharge?
No abstract available.
Authors
James Paces, K.R. Ludwig, Zell Peterman, Leonid A. Neymark, J. Kenneally
The implication of a perched-water system based on USW WT-24 hydrochemistry The implication of a perched-water system based on USW WT-24 hydrochemistry
No abstract available.
Authors
Gary Patterson, Zell Peterman, James Paces
Paleoseismic investigations of Stagecoach Road Fault, southeastern Yucca Mountain, Nye County, Nevada Paleoseismic investigations of Stagecoach Road Fault, southeastern Yucca Mountain, Nye County, Nevada
No abstract available.
Authors
C.M. Menges, J.A. Oswald, J. Coe, S.C. Lundstrom, J.B. Paces, S. A. Mahan, Beth Widmann, Michele Murray
"Overview of calcite/opal deposits at or near the proposed high-level nuclear waste site, Yucca Mountain, Nevada, USA: pedogenic, hypogene, or both" by C.A. Hill, Y.V. Dublyansky, R.S. Harmon, C.M. Schluter "Overview of calcite/opal deposits at or near the proposed high-level nuclear waste site, Yucca Mountain, Nevada, USA: pedogenic, hypogene, or both" by C.A. Hill, Y.V. Dublyansky, R.S. Harmon, C.M. Schluter
No abstract available.
Authors
John Stuckless, Brian Marshall, D. Vaniman, W. Dudley, Zell E. Peterman, James Paces, J. Whelan, Emily Taylor, Richard Forester, D. O’Leary
Non-USGS Publications**
Paces, J.B., Nakai, S., Neal, C.R., Taylor, L.A., Halliday, A.N., and Lee, D-C, 1991, A Sr and Nd isotopic study of Apollo 17 high-Ti basalts: resolution of ages, evolution of magmas, and origins of source heterogeneities: Geochimica et Cosmochimica Acta, v. 55, p. 2025-2043.
Neal, C.R., Taylor, L.A., Davidson, J.P., Holden, P., Halliday, A.N., Paces, J.B., Clayton, R.N., and Mayeda, T.K., 1990, Eclogites with oceanic crustal and mantle signatures from the Bellsbank Kimberlite, South Africa, Part II: Radiogenic isotopes and geochemical evolution: Earth and Planetary Science Letters, v. 99, p. 362-379.
Davis, D.W., and Paces, J.B., 1990, Time resolution of geological events on the Keweenaw Peninsula and implications for development of the Midcontinent Rift system: Earth and Planetary Science Letters, v. 97, p. 54-64.
Paces, J.B., and Bell, K., 1989, Non-depleted sub-continental mantle beneath the Superior Province of the Canadian Shield: Nd-Sr isotopic and trace element evidence from Midcontinent Rift basalts: Geochimica et Cosmochimica Acta, v. 53, p. 2023-2035.
Zolensky, M.E., Sylvester, P.J., and Paces, J.B., 1988, Origin and significance of blue coloration in quartz from Llano Rhyolite (Llanite), north-central Llano County, Texas: American Mineralogist, v. 73, p. 313-323.
Bornhorst, T.J., Kalliokoski, J., and Paces, J.B., 1986, The Keweenaw Native-Copper District, in Brown, A.C., Kirkham, R.V. (eds.), Proterozoic Sediment-hosted Stratiform Copper Deposits of Upper Michigan and Belt Supergroup of Idaho and Montana: Geological Association of Canada/Mineralogical Association of Canada/Canadian Geophysical Union Joint Annual Meeting, Ottawa '86, Field Trip 1 Guidebook, p. 21-36.
McDowell, S.D., and Paces, J.B., 1985, Carbonate alteration minerals in the Salton Sea geothermal system, California, USA: Mineral Magazine, v. 49, p. 469-479.
Wilson, M.L., Paces, J.B., and Ruotsala, A.P., 1984, Fluorapatite from the King Lithia mine, Custer County, South Dakota: Mineral Record v. 15, p. 361-366.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 20
No Result Found
Filter Total Items: 88
Constraints on Quaternary unsaturated- and saturated-zone hydrology from geochronological and isotopic studies of calcite and silica, Yucca Mountain, Nevada Constraints on Quaternary unsaturated- and saturated-zone hydrology from geochronological and isotopic studies of calcite and silica, Yucca Mountain, Nevada
No abstracts available.
Authors
James Paces, Zell Peterman, Leonid A. Neymark, J. Whelan, Brian Marshall
The climatic and hydrologic history of southern Nevada during the Late Quaternary The climatic and hydrologic history of southern Nevada during the Late Quaternary
No abstract available.
Authors
R. Forester, J.P. Bradbury, C. Carter, A. Elvidge-Tuma, M.L. Hemphill, S.C. Lundstrom, S. A. Mahan, B.D. Marshall, L.A. Neymark, J.B. Paces, S.E. Sharpe, J. Whelan, P.E. Wigand
Late Quaternary history of Fortymile Wash in the area near the H-road crossing Late Quaternary history of Fortymile Wash in the area near the H-road crossing
No abstract available.
Authors
Scott Lundstrom, James Paces, Shannon Mahan
U-Pb age evidence for long-term stability of the unsaturated zone at Yucca Mountain U-Pb age evidence for long-term stability of the unsaturated zone at Yucca Mountain
No abstract available.
Authors
Leonid A. Neymark, Y. Amelin, James Paces, Zell Peterman
Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA Geochronologic and isotope studies of calcite and silica constraining Quaternary unsaturated- and saturated zone hydrologic flux at Yucca Mountain, Nevada, USA
Both unsaturated- and saturated-zone aqueous solutions are capable of precipitating secondary mineral deposits that document the history and origins of past water flux. Calcite and opal occur as thin coatings on open fractures and cavity floors within the thick unsaturated zone at Yucca Mountain. Outermost surfaces of calcite have 14C ages of between 44,000 and 16,000 radiocarbon years...
Authors
James Paces, Zell Peterman, Leonid A. Neymark, Joseph Whelan, Brian Marshall
Secondary minerals record past percolation flux at Yucca Mountain, Nevada Secondary minerals record past percolation flux at Yucca Mountain, Nevada
No abstract available.
Authors
Brian Marshall, James Paces, Leonid A. Neymark, J. Whelan, Zell Peterman
Neogene to Quaternary U-Th-Pb geochronology using opal, Yucca Mountain, Nevada, USA Neogene to Quaternary U-Th-Pb geochronology using opal, Yucca Mountain, Nevada, USA
No abstract available.
Authors
Leonid A. Neymark, James Paces, Yu. Amelin
Inferences for Yucca Mountain unsaturated-zone hydrology from secondary minerals Inferences for Yucca Mountain unsaturated-zone hydrology from secondary minerals
No abstract available.
Authors
James Paces, Leonid A. Neymark, Brian Marshall, J. Whelan, Zell Peterman
Anomalous groundwater 234U/238U beneath Yucca Mountain: Evidence for local recharge? Anomalous groundwater 234U/238U beneath Yucca Mountain: Evidence for local recharge?
No abstract available.
Authors
James Paces, K.R. Ludwig, Zell Peterman, Leonid A. Neymark, J. Kenneally
The implication of a perched-water system based on USW WT-24 hydrochemistry The implication of a perched-water system based on USW WT-24 hydrochemistry
No abstract available.
Authors
Gary Patterson, Zell Peterman, James Paces
Paleoseismic investigations of Stagecoach Road Fault, southeastern Yucca Mountain, Nye County, Nevada Paleoseismic investigations of Stagecoach Road Fault, southeastern Yucca Mountain, Nye County, Nevada
No abstract available.
Authors
C.M. Menges, J.A. Oswald, J. Coe, S.C. Lundstrom, J.B. Paces, S. A. Mahan, Beth Widmann, Michele Murray
"Overview of calcite/opal deposits at or near the proposed high-level nuclear waste site, Yucca Mountain, Nevada, USA: pedogenic, hypogene, or both" by C.A. Hill, Y.V. Dublyansky, R.S. Harmon, C.M. Schluter "Overview of calcite/opal deposits at or near the proposed high-level nuclear waste site, Yucca Mountain, Nevada, USA: pedogenic, hypogene, or both" by C.A. Hill, Y.V. Dublyansky, R.S. Harmon, C.M. Schluter
No abstract available.
Authors
John Stuckless, Brian Marshall, D. Vaniman, W. Dudley, Zell E. Peterman, James Paces, J. Whelan, Emily Taylor, Richard Forester, D. O’Leary
Non-USGS Publications**
Paces, J.B., Nakai, S., Neal, C.R., Taylor, L.A., Halliday, A.N., and Lee, D-C, 1991, A Sr and Nd isotopic study of Apollo 17 high-Ti basalts: resolution of ages, evolution of magmas, and origins of source heterogeneities: Geochimica et Cosmochimica Acta, v. 55, p. 2025-2043.
Neal, C.R., Taylor, L.A., Davidson, J.P., Holden, P., Halliday, A.N., Paces, J.B., Clayton, R.N., and Mayeda, T.K., 1990, Eclogites with oceanic crustal and mantle signatures from the Bellsbank Kimberlite, South Africa, Part II: Radiogenic isotopes and geochemical evolution: Earth and Planetary Science Letters, v. 99, p. 362-379.
Davis, D.W., and Paces, J.B., 1990, Time resolution of geological events on the Keweenaw Peninsula and implications for development of the Midcontinent Rift system: Earth and Planetary Science Letters, v. 97, p. 54-64.
Paces, J.B., and Bell, K., 1989, Non-depleted sub-continental mantle beneath the Superior Province of the Canadian Shield: Nd-Sr isotopic and trace element evidence from Midcontinent Rift basalts: Geochimica et Cosmochimica Acta, v. 53, p. 2023-2035.
Zolensky, M.E., Sylvester, P.J., and Paces, J.B., 1988, Origin and significance of blue coloration in quartz from Llano Rhyolite (Llanite), north-central Llano County, Texas: American Mineralogist, v. 73, p. 313-323.
Bornhorst, T.J., Kalliokoski, J., and Paces, J.B., 1986, The Keweenaw Native-Copper District, in Brown, A.C., Kirkham, R.V. (eds.), Proterozoic Sediment-hosted Stratiform Copper Deposits of Upper Michigan and Belt Supergroup of Idaho and Montana: Geological Association of Canada/Mineralogical Association of Canada/Canadian Geophysical Union Joint Annual Meeting, Ottawa '86, Field Trip 1 Guidebook, p. 21-36.
McDowell, S.D., and Paces, J.B., 1985, Carbonate alteration minerals in the Salton Sea geothermal system, California, USA: Mineral Magazine, v. 49, p. 469-479.
Wilson, M.L., Paces, J.B., and Ruotsala, A.P., 1984, Fluorapatite from the King Lithia mine, Custer County, South Dakota: Mineral Record v. 15, p. 361-366.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.