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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. 



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. 



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



USGS Superior Service Award, 2005

GSA Fellow

Colorado Scientific Society President, 2020



Geological Society of America

American Geophysical Union

Geochemical Society

International Association of Geochemistry