Isom Fm, Needles Range Fm, and Bullion Canyon Volcanics

In Cedar City area: Isom Fm and Needles Range Fm (29 my). In Marysvale area: Bullion Canyon Volcanics.
State Utah
Name Isom Fm, Needles Range Fm, and Bullion Canyon Volcanics
Geologic age Late Eocene to Oligocene
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic-tuff, Volcaniclastic-volcanic breccia)Bullion Canyon volcanics, latitic and andesitic
Igneous > Volcanic > Felsic-volcanic (Pyroclastic-tuff, Pyroclastic-ash flow)mostly latite, but also dacite and rhyolite
Minor
Sedimentary > Clastic > Conglomerate (Bed)
References

Hintze, L.F., 1980, Geologic map of Utah: Utah Geological and Mineral Survey, scale 1:500,000.

Hintze, L.F., 1988, Geologic History of Utah: Brigham Young University Geology Studies Special Publication 7, 202 p.

Stevens, T.A., Morris, H.T., and Rowley, P.D., 1990, Geologic map of the Richfield 1øx2ø quadrangle, west-central Utah: U.S. Geological Survey Map I-1901, scale 1:250,000.

https://pubs.er.usgs.gov/publication/i1901

Shubat, M.A., Felger, T.J., and King, J.K., 1999, Geologic map of the Keg Mountain Ranch quadrangle, Juab County, Utah: Utah Geological Survey Miscellaneous Publication 99-5, 22 p, scale 1:24,000

Hintze, L.F., and Davis, Fitzhugh D. D., 2002, Geologic map of the Tule Valley 30' x 60' quadrangle and parts of the Ely, Fish Springs, and Kern Mountains 30' by 60 quadrangles, northwest Millard County, Utah: Utah Geological Survey Map 186, scale 1:100,000.

Oaks, R.Q., Jr., Smith, K.A., Janecke, S.U., Perkins, M.E., and Nash, W.P., 1999, Stratigraphy and tectonics of Tertiary strata of southern Cache Valley, north-central Utah: Utah Geological Association Publication 27, p. 71-110.

Vogel, T.A., Cambray, F.W., and Constenius, K.N., 2001, Origin and emplacement of igneous rocks in the central Wasatch Mountains, Utah: Rocky Mountain Geology, v. 36, no. 2, p. 119-162.

Bryant, B., 1990, Geologic map of the Salt Lake City 30' x 60' quadrangle, north-central Utah, and Uinta County, Wyoming: U.S. Miscellaneous Investigations Series Map I-1944, scale 1:100,000.

Sable, E.G., and Maldonado, F., 1997, The Brian Head Formation (revised) and selected Tertiary sedimentary rock units, Markagunt Plateau and adjacent areas, southwestern Utah, in Maldonado, F., and Nealey, L.D., Geologic Studies in the Basin and Range-Colorado Plateau Transition in Southeastern Nevada, Southwestern Utah, and Northwestern Arizona, 1995: U.S. Geological Survey Bulletin 2153, p. 5-26.

https://pubs.er.usgs.gov/publication/b2153

Smith, K.A., Goessel, K.M., Oaks, R.Q., Jr; Perkins, M.E., and Nash, W. P., 1997, Lenticular Paleogene units in Cache Valley, Utah, constrain tectonic history of northeastern Basin-and-Range Province [abst.]: Geological Society of America Abstracts with Programs, v. 29, no. 6, p. 349.

Rowley, P.D., Mehnert, H.H., Naeser, C.W., Snee, L.W., Cunningham, C.G., Steven, T.A., Anderson, J.J., Sable, E.G., and Anderson, R.E., 1994, Isotopic ages and stratigraphy of Cenozoic rocks in the Marysvale volcanic field and adjacent areas, west-central Utah : U.S. Geological Survey Bulletin 2071, 35 p.

https://pubs.er.usgs.gov/publication/b2071

Hintze, L.F., and Davis, F.D., 2002, Geologic map of the Wah Wah Mountains North 30' x 60' quadrangle and part of the Garrison 30' x 60' quadrangle, southwest Millard County and part of Beaver County, Utah: Utah Geological Survey Map 182, scale 1:100,000.

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Counties Beaver - Garfield - Iron - Kane - Millard - Piute - Sevier - Washington - Wayne