Ash-flow tuffs and tuffaceous sedimentary rocks (NVTts;0)

State	Nevada
Name	Ash-flow tuffs and tuffaceous sedimentary rocks
Geologic age	Middle Miocene to Late Miocene
Original map label	Tts
Comments	Classification schemes don't permit reflection of volcanic origin of the sedimentary rocks. These areas are mixed lacustrine sediments interlayered with the ash-flow tuffs of unit Tt3.
Primary rock type	ash-flow tuff
Secondary rock type	rhyolite
Other rock types	sandstone; dacite; trachyte
Lithologic constituents	Major Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, ash-flow) Minor Sedimentary > Clastic > Sandstone (Tuffaceous) Igneous > Volcanic > Alkalic-volcanic (Pyroclastic, ash-flow) Incidental Igneous > Volcanic > Alkalic-volcanic (Pyroclastic, air fall) Igneous > Volcanic > Alkalic-volcanic (Pyroclastic, tuff) Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, ash-flow) Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, air fall) Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, tuff) Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, ash-flow) Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, air fall) Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, tuff) Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, air fall) Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, tuff)
Map references	Stewart, J.H., and Carlson, J.E., 1978, Geologic Map of Nevada: U.S. Geological Survey and Nevada Bureau of Mines and Geology, 1:500,000 (not part of any formal series, printed and distributed by the U.S. Geological Survey, G75163, reprinted, 1981, G81386).
Unit references	Stewart, J.H., and Carlson, J.E., 1978, Geologic Map of Nevada: U.S. Geological Survey and Nevada Bureau of Mines and Geology, 1:500,000 (not part of any formal series, printed and distributed by the U.S. Geological Survey, G75163, reprinted, 1981, G81386). Stewart, J. H., 1980, Geology of Nevada: A discussion to accompany the Geologic Map of Nevada: Nevada Bureau of Mines and Geology Special Publication 4.
Geographic coverage	Churchill - Elko - Humboldt - Lincoln - Nye - Pershing - Washoe