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Leonid Neymark is a Scientist Emeritus with the Geology, Geophysics, and Geochemistry Science Center.
I am currently a Scientist Emeritus in the Geology, Geophysics, and Geochemistry Science Center after being transferred from the Geochemistry Team, Yucca Mountain Project Branch where I conducted U-series studies of soils, fracture minerals and water-rock interaction processes.
I conduct a wide spectrum of isotope-geochemical studies involving radiogenic isotopes of U, Pb, Sr, and Nd and using ICP-MS and TIMS techniques. Before 2010 I was a principal investigator and a member of the Geochemistry Team in the Yucca Mountain Project Branch, WRD. The team's task was to evaluate geochemical aspects of the hydrogeologic suitability of Yucca Mountain to permanently store high-level radioactive waste. My focus was on the history of secondary mineral deposition (largely calcite and silica) in soil and unsaturated- and saturated-zone settings and on isotope-geochemical indicators of water-rock interaction as evidence of past water flow. These studies used U-Pb and U-series and other isotope-geochemical methods to characterize the timing of low-temperature surface processes of mineral deposition and to evaluate past water-rock interaction. In 2004 I was closely involved in the installation and detailed testing of a new ThermoFinnigan thermal-ionization mass-spectrometer Triton. I developed reproducible mass-spectrometric methods of U-series isotope measurements for whole rock samples with large Th/U and 232Th/230Th ratios. Previous YMPB work included systematic characterization of subsurface and soil hydrogenic minerals to provide a basis for understanding past hydrologic and climate variability in the Yucca Mountain region.
Research Chemist, Geology, Geophysics, and Geochemistry Science Center, USGS
Principal investigator and member of the Geochemistry Team in the Yucca Mountain Project Branch, USGS
2001-2004. S.M. Stoller Corporation, Senior Geochemist
1996-2001. Pacific Western Technologies, Ltd. Senior Scientist
1993-1996. US Geological Survey Visiting Research Scientist
1985-1993. Institute of Precambrian Geology and Geochronology (IPGG), St. Petersburg, Russian Academy of Sciences
1971-1985. All Union Geological Research Institute, Leningrad (USSR Ministry of Geology). Engineer (1971-1981) and Junior Research Scientist (1981-1985)
Ph.D. in Geochemistry, St. Petersburg, Russia
MS degree in Radiochemistry, St. Petersburg, Russia
American Geophysical Union
Geological Society of America
International Geochemistry Association