Geological Society of America

8:00 AM

PER MIL 238U/235U VARIATIONS IN URANIUM ORES: EVIDENCE FOR ISOTOPIC FRACTIONATION BY NUCLEAR FIELD SHIFT?

Charles John Bopp, UIUC, Urbana, IL and Craig Lundstrom, University of Illinois Dept of Geology, Urbana, IL

124302 (Technical Sessions)

8:15 AM

APPLICATION OF X-RAY MICRO-COMPUTED TOMOGRAPHY IN (U-TH)/HE THERMOCHRONOLOGY

Brent I.A. McInnes, CSIRO Exploration and Mining, Bentley, WA, N/A and Noreen J. Evans, Curtin University, Bentley, WA and Peter J. Austin, CSIRO Minerals, Waterford, N/A and Andrew Squelch, CSIRO Exploration and Mining, Bentley, Perth, N/A and Bradley J. McDonald, CSIRO Exploration and Mining, Bentley, WA, N/A and Qianhong Wu, Central South University, Changsha, Hunan, N/A

129810 (Technical Sessions)

8:30 AM

THE EFFECT OF GRAIN SIZE ON THE CLOSURE TEMPERATURE OF HE IN CALCITE: A CASE STUDY FROM THE MIOCENE BARSTOW FORMATION

Peter Copeland, Univ. of Houston Earth and Atmospheric Sci., Houston, TX and Troy Rasbury, Stony Brook University, Stony Brook, NY and E. Bruce Watson, Rensselaer Polytechnic Institute, Troy, NY

131209 (Technical Sessions)

8:45 AM

MODELING DIFFUSION PHENOMENA IN MINERALS: THE CASE OF HELIUM IN ZIRCON (U-TH)/HE THERMOCHRONOMETER

Martin Reich, School of Engineering and Science, University of Chile, Santiago and Rodney C. Ewing, University of Michigan, Ann Arbor, MI and Todd A. Ehlers, University of Michigan, Ann Arbor, MI and Udo Becker, Univ of Michigan, Ann Arbor, MI

128378 (Technical Sessions)

9:00 AM

RADIOLYTIC OXIDATION OF PYRITE BY GAMMA RADIATION

Liliana Lefticariu, Southern Illinois University Geology Department, Carbondale, IL and Lisa Pratt, Dept. of Geological Sciences, Bloomington, IN and Edward Ripley, Indiana University, Bloomington, IN and Jay LaVerne, University of Notre Dame, Notre Dame, IN

123149 (Technical Sessions)

9:15 AM

THERMOBAROMETRY OF >4 GA ZIRCONS: TOWARDS A HADEAN GEOTHERM

M.D. Hopkins, University of California, Los Angeles, Los Angeles, CA and T.M. Harrison, University of California,Los Angeles, Los Angeles, CA

129077 (Technical Sessions)

9:30 AM

CONCENTRATION AND CARBON ISOTOPE COMPOSITION OF FE(CO3)OH IN PEDOGENIC GOETHITE OF A MID-CRETACEOUS PALEOSOL IN SOUTHWESTERN MINNESOTA

Weimin Feng, University of Texas at Austin, Austin, TX and Crayton Yapp, Dallas, TX

125158 (Technical Sessions)

10:00 AM

OXYGEN ISOTOPE DATA FROM HYDROTHERMALLY ALTERED ARCHEAN PLUTONS: CONSTRAINTS ON THE ISOTOPIC EVOLUTION OF THE HYDROSPHERE

Sandeep Banerjee, Southern Methodist University, Dallas, TX and Robert T. Gregory, Southern Methodist University, Dallas, TX and Ian Richards, Southern Methodist University, Dallas, TX and Kurt Ferguson, Southern Methodist University, Dallas, TX

128882 (Technical Sessions)

10:15 AM

SEA SURFACE TEMPERATURE CHANGE FROM LATE ORDOVICIAN δ18O DATA, BROMIDE AND VIOLA SPRINGS FORMATIONS, OKLAHOMA, USA

Nicholas A. Rosenau, University of Arkansas at Little Rock, Little Rock, AR and Stephen A. Leslie, James Madison University, Harrisonburg, VA and Achim Herrmann, Louisiana State University Department of Geology and Geophysics, Baton Rouge, LA

130243 (Technical Sessions)

10:30 AM

MOLECULAR SIGNATURES FOR CHANGES IN POPULATIONS OF NITROGEN-FIXING CYANOBACTERIA IN RESPONSE TO FLUCTUATIONS IN OXYGENATION LEVELS DURING THE EARLY APTIAN OCEANIC ANOXIC EVENT

Simon C. Brassell, Indiana Univ, Bloomington, IN and Mirela Dumitrescu, ExxonMobil Exploration Company, Houston, TX

131402 (Technical Sessions)

10:45 AM

d15N AND d18O OF NITRATE AND THE INFLUENCE OF ANTHROPOGENIC INPUTS ON THE SURFACE WATER NITRATE BUDGET IN ANCHORAGE, ALASKA, USA

Derek Sjostrom, Rocky Mountain College, Billings, MT and LeeAnn Munk, University of Alaska Anchorage, Anchorage, AK

126444 (Technical Sessions)

11:00 AM

LATTICE BOLTZMANN SIMULATION OF OXYGEN- AND HYDROGEN-ISOTOPE FRACTIONATIONS DURING SNOW CRYSTAL FORMATION

Guoping Lu, Lawrence Berkeley National Laboratory, Berkeley, CA and Donald J. DePaolo, Lawrence Berkeley National Laboratory, Berkeley, CA