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National Geologic Map Database
Geologic Unit: Nopah
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Map showing publication footprint
  • Usage in publication:
    • Nopah Dolomite*
  • Modifications:
    • Areal extent
    • Overview
    • Redescribed
  • Dominant lithology:
    • Dolomite
  • AAPG geologic province:
    • Great Basin province
Publication:

Hintze, L.F., and Axen, G.J., 1995, Geologic map of the Scarecrow Peak Quadrangle, Washington County, Utah, and Lincoln County, Nevada: U.S. Geological Survey Geologic Quadrangle Map, GQ-1759, 1 sheet, scale 1:24,000 [http://ngmdb.usgs.gov/Prodesc/proddesc_307.htm]


Summary:

Mapped in Lincoln Co, NV, Great Basin province; exposed in southwest quarter of quad. Redescribed; lower 60 m consists of light-gray, coarse-grained, massive dolomite and upper 60 m consists of dark gray, coarse-grained, thick-bedded to massive, locally cherty dolomite that is commonly mottled, and includes "tiger-stripped" zones of secondary dolomitization. Lower part is incompletely exposed. Nopah is commonly tectonically brecciated; breccia is recemented forming resistant ledges and cliffs. No fossils found in this quad though silicified brachiopods EOORTHIS sp. found in adjacent Lime Mountain quad. Unit is about 120 m thick. Nopah is oldest exposed unit; conformably underlies lower part of Pogonip Group. Late Cambrian age.

Source: GNU records (USGS DDS-6; Denver GNULEX).


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).