Table 1. Radiohalos identified and counted in granitic rocks spanning the geologic record from the Archean to the present. Rock Unit Location “Age” Samples (slides) Radiohalos Number of Radiohalos per Slide Number of Po Radiohalos per Slide Ratios 210Po 214Po 218Po 238U 232Th 210Po:238U 210Po:214Po 210Po:218Po 238U:232Th Kingston Granite Kingston Range, CA Miocene 1 (50) 0 0 0 0 0 0 0 -- -- -- -- Granite Phoenix, AZ Early Miocene- Oligocene 2 (100) 0 0 0 0 0 0 0 -- -- -- -- Index Granite Cascades, WA Oligocene (33 Ma) 1 (50) 9 0 0 2 0 0.22 0.18 4.5:1 -- -- -- Spry Granite Panguitch, UT Oligocene 1 (50) 0 0 0 0 0 0 0 -- -- -- -- Granite Salt Lake, UT Tertiary 1 (50) 0 0 0 0 0 0 0 -- -- -- -- Chelan Granite Pateros area, WA PaleoceneCretaceous 2 (100) 0 0 0 0 0 0 0 -- -- -- --- Granite Phoenix, AZ Late Cretaceousearly Tertiary 1 (50) 0 0 0 0 0 0 0 -- -- -- -- Bitterroot Batholith Idaho, USA 70-90 Ma 4 (200) 38 0 0 18 0 0.28 0.19 2.1:1 -- -- -- Joseph Pluton, Idaho Batholith Montana, USA 70-90 Ma 1 (50) 0 0 0 0 0 0 0 -- -- -- -- Butte Quartz Monzonite Montana, USA 73-78 Ma 2 (100) 26 0 0 1 0 0.27 0.26 26:1 -- -- -- Mt Stuart Granite Washington, USA 88 Ma 1 (50) 0 0 0 0 0 0 0 -- -- -- -- Black Peak Batholith Washington, USA Late Cretaceous 1 (50) 1 0 0 2 0 0.06 0.02 0.5:1 -- -- -- Golden Horn Granite 1 (50) 7 0 0 1 0 0.2 0.14 7:1 -- -- -- Seoul Granite Seoul, South Korea Late Cretaceous 1 (50) 300 0 0 171 0 9.42 6.0 1.75:1 -- -- -- Indian Hill Granite San Diego County, USA 90 Ma 4 (180) 279 11 0 45 0 1.86 1.61 6.2:1 25.4:1 -- -- La Posta Pluton 93 Ma 8 (383) 96 4 0 8 0 0.3 0.26 8:1 24:1 -- -- Granodiorite of Mono Dome Yosemite, USA 93 Ma 1 (50) 6 0 0 0 0 0.1 0.1 -- -- -- -- San Jacinto Pluton Palm Springs, USA Late Cretaceous 9 (450) 96 0 0 9 0 0.22 0.21 10.7:1 -- -- -- Johnson Granite Porphyry Yosemite, USA 85-86 Ma 1 (50) 58 0 0 6 0 3.26 3.14 26:1 -- -- - Cathedral Peak Granite Yosemite, USA 87-88 Ma 2 (100) 325 0 0 6 0 3.31 3.25 54:1 -- -- -- Half Dome Granodiorite Yosemite, USA 89-91 Ma 2 (100) 55 1 0 30 0 0.82 0.53 1.8:1 -- -- -- Granodiorite of Kuna Crest Yosemite, USA 93-95 Ma 3 (150) 5 0 0 3 0 0.05 0.03 1.7:1 -- -- -- Yosemite Creek Granodiorite Yosemite, USA ~93-95 Ma 2 (100) 8 0 0 0 0 0.08 0.08 -- -- -- -- Sentinel Granodiorite Yosemite, USA ~93 Ma 3 (150) 29 0 0 29 0 0.39 0.19 1:1 -- -- -- Taft Granite Yosemite, USA ~96 Ma 1 (50) 58 0 0 6 0 1.28 1.16 9.7:1 -- -- -- Granodiorite of Illilouette Creek Yosemite, USA ~100 Ma 2 (100) 24 0 0 8 0 0.32 0.24 3:1 -- -- -- El Capitan Granite Yosemite, USA ~102 Ma 4 (200) 179 0 0 17 0 0.98 0.90 10.5:1 -- -- -- Bass Lake Tonalite Yosemite, USA 114 Ma 1 (50) 84 0 0 0 3 1.7 1.68 -- -- -- -- Ward Mountain Trondhjemite Yosemite, USA 115 Ma 1 (50) 63 0 0 0 0 1.26 1.26 -- -- -- -- Granodiorite of Arch Rock Yosemite, USA 114-117 Ma 2 (100) 106 0 7 10 0 1.23 1.13 10.6:1 -- 15.1:1 -- Tonalite of the Gateway Yosemite, USA 114-117 Ma 2 (100) 1 0 0 0 0 0.01 0.01 -- -- -- -- Conway Granite New Hampshire, USA 175-188 Ma 9 (450) 1649 137 5 946 0 6.08 3.98 1.74:1 12:1 330:1 -- SNELLING Radiohalos through earth history 2023 ICC 547
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