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Shale, chert, and minor amounts of quartzite, greenstone, and limestone

SHALE, CHERT, AND MINOR AMOUNTS OF QUARTZITE, GREENSTONE, AND LIMESTONE-Includes units such as Vinini Formation of north-central Nevada, Palmetto Formation in southern and central parts of Esmeralda County, and Comus Formation in Humboldt County. Locally includes rocks of Silurian and Devonian age.
State Nevada
Name Shale, chert, and minor amounts of quartzite, greenstone, and limestone
Geologic age Ordovician
Comments Shale and siltstone in the Palmetto Formation have locally been metamorphosed to hornfels (Albers and Stewart, 1972). The Comus Formation is approximately 25% limestone, 40% dolomite, and 35% shale; it ranges from 3,000 to 5,450 feet thick but makes up only an incidental part of this unit (Willden, 1964). A small portion of the Palmetto Formation in Esmeralda County has been assigned to NVOsv (Albers and Stewart, 1972).
Primary rock type chert
Secondary rock type shale
Other rock types limestone; quartzite; andesite; siltstone; sandstone; chemical; greenstone; dolostone (dolomite)
Lithologic constituents
Major
Sedimentary > Chemical > Chert (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)Primarily black shale but also cherty and argilliceous.
Minor
Sedimentary > Carbonate > Limestone (Bed)
Metamorphic > Quartzite
Incidental
Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)
Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic, tuff)
Metamorphic > Greenstone (Greenschist)
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Carbonate > Dolostone (Bed)Limited to Comus Formation.
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.
Stewart, J.H., and McKee, E.H., 1977, Geology, Pt. 1, in Geology and Mineral Deposits of Lander County, Nevada: Nevada Bureau of Mines and Geology Bulletin 88, p. 1-59, 3 pl.
Willden, R., 1964, Geology and Mineral Deposits of Humboldt County, Nevada: Nevada Bureau of Mines and Geology Bulletin 59, 154 p., 3 pl.
Coats, R.R., 1987, Geology of Elko County, Nevada: Nevada Bureau of Mines and Geology Bulletin 101, 112 p., 1 pl.
Albers, J.P., and Stewart, J.H., 1972, Geology and Mineral Deposits of Esmeralda County, Nevada: Nevada Bureau of Mines and Geology, 80 p., 2 pl.
Kleinhampl, F.J., and Ziony, J.I., 1985, Geology of Northern Nye County, Nevada: Nevada Bureau of Mines and Geology Bulletin 99A, 172 p., 2 pl.
Counties Elko - Esmeralda - Eureka - Humboldt - Lander - Mineral - Nye