Quaternary and Pliocene Yellowstone volcanic field of Wyoming, Idaho, and Montana
Christiansen RL. 1994. Quaternary and Pliocene Yellowstone volcanic field of Wyoming, Idaho, and Montana. U.S. Geological Survey (USGS) Professional Paper. 729-G. United States Government Printing Office
The rhyolite plateau of Yellowstone National Park and nearby areas is part of the latest Pliocene and Quaternary Yellowstone Plateau volcanic field, which originally covered nearly 17,000 km2 but has since been disrupted by erosion and by continued volcanism and tectonism. Igneous rocks of the field consist predominantly of rhyolites and subordinately of basalts; there are virtually none of intermediate compositions. The rhyolites comprise numerous lava flows and three major sheets of welded ash-flow tuff sepa- rated by unconformities. Stratigraphically these sheets— from oldest to youngest, the Huckleberry Ridge, Mesa Falls, and Lava Creek Tuffs—constitute the Yellowstone Group. The geologic history of the field defines three cycles, in each of which the sequence of volcanic events was similar, climaxed by the eruption of a voluminous sheet of rhyolitic ash-flow tuff and the formation of a large caldera. Preceding and succeeding events included eruptions of rhyolitic lavas and tuffs in and near the source areas of the ash-flow sheets and the eruption of basalts around the margins of major rhyolitic volcanism.
- Type
- Published Report
- Authors
- Christiansen, Robert
- Date of Issue
- 1994
- Publisher
- United States Government Printing Office
- Units
- HIST , YELL
- Keywords
- Basalts, Calderas, ehistory, Geology, Geothermal Activity, History, Igneous Rocks, Magma, Magmotectonic evolution, Petrology, Pliocene, Quaternary, Rhyolites, Rocks, Volcanic Activity, volcanic history, Yellowstone Plateau