Rhyolitic tuffs, ignimbrites, and flows, basaltic flows, conglomerate and marlstone; Pliocene to Miocene volcano-sedimentary deposits; eastern Snake River Plain and southeastern Idaho (IDTpmv;0)

State	Idaho
Name	Rhyolitic tuffs, ignimbrites, and flows, basaltic flows, conglomerate and marlstone; Pliocene to Miocene volcano-sedimentary deposits; eastern Snake River Plain and southeastern Idaho
Geologic age	Pliocene-Miocene
Original map label	Tpv; Ti
Comments	Starlight Fm is predominantly volcanic (rhyolitic tuff, ash-flow tuff, and basalt) but has a basal diamictite, and upper marl. Age determinations (7.0-10.2 Ma) indicate Late Miocene age, but is interlayered with Pliocene Salt Lake Fm (tuffaceous sedimentary section, and fossils indicate Pliocene age). Rhyolitic tuffs, ash-flow tuffs above the Starlight Fm are from the Heise volcanic center (4.3-6.7 Ma). Overlying basalt of Buckskin Basin is 2.2 to 3.7 Ma (ID129).
Primary rock type	rhyolite
Secondary rock type	tuff
Other rock types	ignimbrite; tholeiite; conglomerate; marlstone
Lithologic constituents	Incidental Sedimentary > Carbonate > Marlstone (Bed)marl interlayered with upper friable tuff
Map references	Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000.
Unit references	Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000. Oriel, S.S., and Platt, L.B., 1980, Geologic map of the Preston 1o x 2o quadrangle, southeastern Idaho and western Wyoming: U.S. Geological Survey Miscellaneous Investigations Series, Map I-1127, scale 1:250,000. [http://pubs.er.usgs.gov/publication/i1127] Rember, W.C., and Bennett, E.H., 1979, Geologic map of the Pocatello quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Pocatello 2o quadrangle, scale 1:250,000. Mitchell, V.E., and Bennett, E.H., 1979, Geologic map of the Driggs quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Driggs 2o Quadrangle, scale 1:250,000. Carr, W.J. and Trimble, D.E., 1963, Geology of the American Falls quadrangle, Idaho: in Contributions to General Geology, 1960: U.S. Geological Survey Bulletin, 1121-G, p. G1-G44. [http://pubs.er.usgs.gov/publication/b1121G] Kellogg, K.S. and Marvin, R.S., 1988, New potassium-argon ages, geochemistry, and tectonic setting of upper Cenozoic volcanic rocks near Blackfoot, Idaho: U.S. Geological Survey Bulletin 1806, 19 p. [http://pubs.er.usgs.gov/publication/b1806] Kellogg, K.S., Harlan, S.S., Mehnert, H.H., Snee, L.W., Pierce, K.L., Hackett, W.R., and Rodgers, D.W., 1994, Major 10.2-Ma rhyolitic volcanism in the eastern Snake Rver Plain, Idaho: Isotopic age and stratigraphic setting of the Arbon Valley Tuff Member of the Starlight Formation: U.S. Geological survey Bulletin 2091, 18 p.
Geographic coverage	Bannock - Butte - Oneida - Power