Figure of western U.S showing the track of the Yellowstone hotspot as
assumed by younging in a northeast direction of silicic calderas (yellow).
Areas colored in shades of tan represent Neogene sedimentary deposits contemporaneous
with the hotspot volcanism. Black dots are sampling locations of Yellowstone/Snake
River Plain volcanic ash deposits. All radiometric ages for units in the
interval including 4.49 Ma to 10.27 Ma are ages determined by Ar/Ar analysis
at the Lamont-Doherty Earth Observatory Geochronology Laboratory and the
at the Berkeley Geochronology Center. Many age determinations are
based on weighted averages of as many as 16 individual age determinations.
LC = 0.60 Ma Lava Creek Tuff
MF = 1.29 Ma Mesa Falls Tuff HR = 2.00 Ma Huckleberry Ridge Tuff H = 4.49 Ma tuff of Heise Ek = 5.37 Ma tuff of Elkhorn Springs WC = 5.81 Ma tuff of Wolverine Creek CC = 5.94 Conant Creek Tuff BC = 6.19 Ma tuff of Blue Creek W = 6.19 Ma Walcott Tuff ES = 6.57 Ma tuff of Edie School |
AF = 7.48 Ma tuff of America Falls
KC = 9.17 Ma tuff of Kyle Canyon LR = 8.75 Ma tuff of Lost River Sinks Ch = 9.34 Ma tuff of Little Chokecherry Canyon AV = 10.09 Ma and 10.27 Ma tuff of Arbon Valley A & B Tw = 8.6 to10 Ma Twin Fall Caldera Br-Ja = 10.0 to 12.5 Ma Bruneau-Jarbridge Caldera Ow-Hu = ~13.9 to 12.8 Ma Owyhee-Humbolt Caldera M = 16.1 Ma McDermitt Caldera |