Revised ages for tuffs of the Yellowstone Plateau volcanic field; assignment of the Huckleberry Ridge Tuff to a new geomagnetic polarity event
Lanphere, Marvin A; Champion, Duane E; Christiansen, Robert L; Izett, Glen A; Obradovich, John D (2002) Revised ages for tuffs of the Yellowstone Plateau volcanic field; assignment of the Huckleberry Ridge Tuff to a new geomagnetic polarity event. Geological Society of America Bulletin, vol.114, no.5, pp.559-568, May 2002
| Authors | Lanphere, Marvin A; Champion, Duane E; Christiansen, Robert L; Izett, Glen A; Obradovich, John D |
|---|---|
| Year | 2002 |
| Title | Revised ages for tuffs of the Yellowstone Plateau volcanic field; assignment of the Huckleberry Ridge Tuff to a new geomagnetic polarity event |
| Source | Geological Society of America Bulletin, vol.114, no.5, pp.559-568, May 2002 |
| ISSN | 0016-7606 |
| GeoRef | 2002-035487 |
| Keywords | absolute age; age; alkali feldspar; Ar/Ar; ash-flow tuff; BeaverheadCounty Montana; Cenozoic; dates; feldspar group; framework silicates;Gallatin County Montana; Huckleberry Ridge Tuff; igneous rocks; LavaCreek Tuff; magnetostratigraphy; Mesa Falls Tuff; Montana; nationalparks; paleomagnetism; Park County Montana; Park County Wyoming;public lands; pyroclastics; Quaternary; Reunion Subchron; revision;sanidine; silicates; Teton County Wyoming; tuff; United States;volcanic fields; volcanic rocks; Wyoming; Yellowstone Group Tuff;Yellowstone National Park; Yellowstone National Park County Montana;Yellowstone Plateau |
| DOI | 10.1130/0016-7606(2002)114<0559:RAFTOT>2.0.CO;2 |
Abstract
super 40 Ar/ super 39 Ar ages were determined on the three majorash-flow tuffs of the Yellowstone Plateau volcanic field in the regionof Yellowstone National Park in order to improve the precision ofpreviously determined ages. Total-fusion and incremental-heating agesof sanidine yielded the following mean ages: Huckleberry RidgeTuff--2.059 + or - 0.004 Ma; Mesa Falls Tuff--1.285 + or - 0.004 Ma;and Lava Creek Tuff--0.639 + or - 0.002 Ma. The Huckleberry Ridge Tuffhas a transitional magnetic direction and has previously been relatedto the Reunion Normal-Polarity Subchron. Dating of the Reunion eventhas been reviewed and its ages have been normalized to a common valuefor mineral standards. The age of the Huckleberry Ridge Tuff issignificantly younger than lava flows of the Reunion event on ReunionIsland, supporting other evidence for a normal-polarity event youngerthan the Reunion event.