New Production Rate Estimates for In Situ Cosmogenic 14 C Cronus-Earth/EU Workshop, Vancouver, July Bailey Dugan, Nathaniel Lifton, A.J. Timothy Jull University of Arizona 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 CRONUS-Earth 49.7 ± 1.3 w/05PPT ± 0.8 w/o 05PPT ± 1.3 w/05PPT ± 0.8 w/o 05PPT-02

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 CRONUS-Earth  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

Scale to SLHL