Metamorphic zircon in mafic rocks of the Mariánské Lázně Complex, as well as monazite from orthogneiss, and titanite in leucosome yield ages around 380 Ma.On the basis of detailed petrography and cathodoluminescence imaging we conclude that the . Most absolute dating techniques are based on radioactive decay. Discovery of radioactivity in 1896 finally provided the elusive "rock clock". Objective: To assign numerical ages geologic events.Projects I am currently or recently (last 4 years) involved in include: • Geologic Mapping Studies at Buffalo National River, AR (Funding source: USGS-GEC SC) • Greater Platte River Basins and N.
Panaji is the state's capital, while Vasco da Gama is its largest city. Tenn.; Sr-Nd isotopes of Apollo 17 basalts 1990-1992: Postdoc, USGS, Branch of Isotope Geology: Lower crustal nodules from Michigan kimberlites; High-precision U-Pb dating of Duluth Complex single zircons 1992-2010: USGS, Yucca Mtn. B., 1985, Carbonate alteration minerals in the Salton Sea geothermal system, California, USA. Project Branch: Site characterization studies (paleoseismicity, geomorphology, groundwater and vadose-zone hydrology, paleoclimate) focusing on U-series isotope approaches 2010-2014: USGS, Geosciences and Environmental Change Science Center: Various studies of climate change, landscape evolution, paleoseismicity, paleontology, and water sources/flow processes using U-series- and Sr-isotope data obtained from opaline silica, tufa, travertine, speleothems, bone, paleosols, peat, and water Research Geologist, USGS, Geology and Environmental Change Science Center, (2010 to 2014)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. Research involved both surface- and subsurface-based investigations of geochronology, hydrology, and paleoclimate using natural isotopes of strontium and the uranium-series disequilibrium chain for tracing hydrologic pathways and for isotopic dating a wide range of hydrogenic deposits. Council Post-doc, USGS, Branch of Isotope Geology (1990 to 1991)1) Geochemical, isotopic (Pb, Sr, Nd), and geochronological investigation of granulite nodules from southern Superior Province kimberlites. to Dec., 1989)Collected Sr and Nd isotope compositions on whole rocks and mineral separates of Apollo 17 mare basalts and interpreted results with respect to eruptive ages and mantle differentiation events. P., 1984, Fluorapatite from the King Lithia mine, Custer County, South Dakota. Major tasks included (1) providing paleoenvironmental histories and the timing of seismic events by dating surface deposits at numerous faults across the site, (2) understanding the paleohydrologic significance of secondary minerals in the deep unsaturated zone (UZ) in terms of the timing and amounts of percolation flux, sources of fracture water, and impacts of climate change on deep UZ flow, (3) determine the degrees of Pleistocene water-rock interaction to evaluate UZ-flow processes such as flow focusing in fault zones and fractures, capillary barrier effects, extent of past water-table rises beneath the repository, (4) defining flow paths in the regional saturated-zone ground-water system, and (5) studying the history and nature of Pleistocene discharge deposits in nearby areas to determine how the regional ground-water system responded to Pleistocene climate change. 2) High-precision, single-zircon U-Th-Pb geochronological study of mafic intrusive rocks of the 1.1 Ga Duluth Complex that led to major rethinking of magma generation and differentiation processes during Midcontinent Rifting. AWARDS USGS Superior Service Award – August 2005 – for development and application of innovative U-series disequilibrium analyses PROFESSIONAL AFFILIATIONSGeological Society of America American Geophysical Union Geochemical Society International Association of Geochemistry Publications: Wilson, M.