Ash-flow tuffs and tuffaceous sedimentary rocks

ASH-FLOW TUFFS AND TUFFACEOUS SEDIMENTARY ROCKS
State Nevada
Name Ash-flow tuffs and tuffaceous sedimentary rocks
Geologic age Middle Miocene to Late Miocene
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
Igneous > Volcanic > Alkalic-volcanic (Pyroclastic, ash-flow)
Sedimentary > Clastic > Sandstone (Tuffaceous)
Incidental
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, tuff)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, air fall)
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, tuff)
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, air fall)
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, ash-flow)
Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, tuff)
Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, air fall)
Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, ash-flow)
Igneous > Volcanic > Alkalic-volcanic (Pyroclastic, tuff)
Igneous > Volcanic > Alkalic-volcanic (Pyroclastic, air fall)
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.
Counties Churchill - Elko - Humboldt - Lincoln - Nye - Pershing - Washoe