http://SaturnianCosmology.Org/ mirrored file For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== pmc logo image Logo of pnas Table 1 Analytical data for K-Ar ages on Pleistocene lava flows of the Grand Canyon, Arizona Mile^* Flow ^40Ar[rad], % Age^â , Ma Gray Ledge Dam 187.2 â 6.5 0.788 ± 0.128 Massive Diabase Dam 202.5N â 5.5 0.421 ± 0.082 3.9 0.430 ± 0.121 184.5N â 9.0 0.496 ± 0.057 2.8 0.291 ± 0.113 Layered Diabase Dam 183.2S Flow 2 6.9 0.542 ± 0.083 6.4 0.729 ± 0.120 183.3S Flow 7 5.7 0.657 ± 0.124 6.3 0.636 ± 0.107 D Dam 179.7N Flow D 12.1 0.580 ± 0.049 14.4 0.584 ± 0.040 Buried Canyon Dam 183.1N Flow I 2.7 1.190 ± 0.480 1.7 1.410 ± 0.890 1.6 0.469 ± 0.324 12.3 0.992 ± 0.082 183.0N Flow F1 1.5 2.240 ± 1.620 4.0 0.921 ± 0.247 183.1N Flow D 1.7 1.770 ± 1.140 1.1 0.920 ± 0.890 7.5 1.270 ± 0.180 183.1N Flow D 3.1 0.838 ± 0.291 183.0N Flow C 6.2 0.626 ± 0.107 2.8 0.903 ± 0.355 183.1N Flow A 2.4 4.780 ± 2.190 4.3 1.020 ± 0.260 Esplanade Dam 181.0N Flow B 2.3 0.110 ± 0.053 Ponderosa Dam 181.6N â 7.2 0.591 ± 0.033 7.2 0.625 ± 0.035 Toroweap Dam 179.8S Hi-remnant F 2.7 1.170 ± 0.470 3.4 1.320 ± 0.420 4.4 0.484 ± 0.119 179.8S Hi-remnant F 6.1 1.180 ± 0.210 179.8S Hi-remnant F 7.9 0.677 ± 0.090 6.7 0.689 ± 0.109 178.5N Flow E 2.2 1.200 ± 0.610 4.1 1.730 ± 0.460 178.5N Flow E 5.6 0.398 ± 0.075 4.7 0.376 ± 0.086 3.1 0.905 ± 0.318 Lava Butte Dam 181.0N Flow 1 6.3 0.659 ± 0.043 5.4 0.511 ± 0.038 181.0N Flow 2 4.4 0.581 ± 0.052 7.2 0.840 ± 0.046 181.0N Flow 3 3.7 0.569 ± 0.060 6.1 0.408 ± 0.031 181.0N Flow 4 7.2 0.652 ± 0.037 Upper Prospect Canyon flow â 6.8 0.524 ± 0.082 8.9 0.488 ± 0.057 Prospect Canyon Dam 179.0S Youngest flow 18.7 0.653 ± 0.034 13.9 0.596 ± 0.043 6.6 0.416 ± 0.067 179.6S Old fill 2.4 0.885 ± 0.410 5.6 0.889 ± 0.170 179.0S Oldest flow 6.2 1.860 ± 0.300 179.0S Oldest flow 5.0 0.657 ± 0.052 6.5 0.869 ± 0.052 179.0S Oldest flow 5.0 0.946 ± 0.074 3.1 0.745 ± 0.103 Toroweap Valley Fill â 3.8 0.780 ± 0.224 4.7 0.774 ± 0.176 4.7 3.770 ± 0.860 Dike, Prospect Canyon 179.5S Hi dike 12.7 0.851 ± 0.067 12.6 0.750 ± 0.120 ^*The lava dams and the individual flows are listed in stratigraphic order, from youngest to oldest, where known. N, north side of canyon; S, south side of canyon. ^â ^40K/K[total] = 1.167 à 10^â4, λ[ [var epsilon] ]= 0.581 à 10^â10 [center dot] yr^â1, λ[β] = 4.692 à 10^â1 [center dot] yr^â1. Errors assigned to individual ages are estimates of the analytical precision at the 68% confidence level. Proc Natl Acad Sci U S A. 1998 August 18; 95(17): 9744â9749. Copyright © 1998, The National Academy of Sciences