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New Production Rate Estimates for In Situ Cosmogenic 14 C. Bailey Dugan, Nathaniel Lifton, A.J. Timothy Jull University of Arizona. Cronus-Earth/EU Workshop, Vancouver, July 12-13 2008. Funded By The U.S. National Science Foundation. Promontory Point Results.
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New Production Rate Estimates for In Situ Cosmogenic 14C Bailey Dugan, Nathaniel Lifton, A.J. Timothy Jull University of Arizona Cronus-Earth/EU Workshop, Vancouver, July 12-13 2008 Funded By The U.S. National Science Foundation
Promontory Point Results • Site Production Rates Generally Consistent w/Earlier Estimates • Replicates • Unexplained Variability • Use Weighted Means • 05PPT-02 • Replicates Agree • >2 Below Site Weighted Mean • No Obvious Reason • Higher Position on 05PPT-01 Outcrop • Excluded from Further Analysis • Additional Analyses Planned 49.7 ± 1.3 w/05PPT-02 51.4 ± 0.8 w/o 05PPT-02 CRONUS-Earth
Corrie Nan Arr Results • Good Agreement Between Supra- and Sub-Glacial Boulders • Supports Assumption of Landslide Deposition on Retreating Glacier • Additional Analyses Planned CRONUS-Earth
Maol Chean-Dearg (Mull Kin Jerig)Results • Site Production Rates Show Generally Good Agreement • Replicates • Unexplained Variability • Use Weighted Means • Additional Analyses Planned CRONUS-Earth
Sea Level, High Latitude (SLHL)Production • Four Scaling Models Compared • Lal (1991)/Stone(2000) • Dunai (2001) • Desilets & Zreda (2003)/Desilets et al. (2006) • Lifton et al. (2005) • Variable Atmosphere Assumed for All • Geomagnetic Assumptions • Geocentric Axial Dipole for Lal/Stone • Continuous Geomagnetic Model of Lifton et al. (2008) for Others CRONUS-Earth