Response to Comments on “Apatite 4 He/ 3 He and (U-Th)/He Evidence for an Ancient Grand Canyon” by R. M. Flowers, and K. A. Farley Science Volume 340(6129): April 12, 2013 Published by AAAS
Fig. 1 Grand Canyon shaded relief map showing all western canyon-bottom sample locations, mean AHe dates, uncertainties, and number of individual analyses.Gray box denotes the anomalous western canyon sample, which is characterized by extreme AHe data scatter, and forms the basis of the arguments in Karlstrom et al. R. M. Flowers, and K. A. Farley Science 2013;340:143 Published by AAAS
Fig. 2 Thermal history simulation results for the western and eastern Grand Canyon.(A) Western canyon-bottom thermal history results from (1) (upper panel) compared with simulation results using only the normalized 4He/3He step age profiles [goodness-of-fit parameter G = 0.32 (1)] and AHe data (G = 0.3) for sample CP R. M. Flowers, and K. A. Farley Science 2013;340:143 Published by AAAS