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National Geologic Map Database
Geologic Unit: Chiulos
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Map showing publication footprint
  • Usage in publication:
    • Chiulos shale member*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Great Basin province
    • South Western Overthrust
Publication:

Cohenour, R.E., 1959, Sheeprock Mountains, Tooele and Juab Counties, Utah; Precambrian and Paleozoic stratigraphy, igneous rocks, structure, geomorphology, and economic geology: Utah Geological and Mineral Survey Bulletin, no. 63, 201 p., (incl. geologic map, scale 1:135,000)


Summary:

Pg. 12 (table 1), 90-93, 170, 172, 174-175, pls. 1, 21. Chiulos shale member of Great Blue Formation. Primarily black fissile shale with many interbedded ribs of quartzite near center. Thickness about 1,818 feet. Overlies a lower limestone member about 911 feet thick; in fault contact with upper limestone member that is about 1,410 feet thick. Age is Late Mississippian. Name credited to USGS.
[Notable expousres in Sheeprock Mountains, Tooele and Juab Cos., Wasatch National Forest, western UT.]

Source: US geologic names lexicon (USGS Bull. 1200, p. 785).


Map showing publication footprint
  • Usage in publication:
    • Chiulos member*
  • Modifications:
    • Principal reference
  • Dominant lithology:
    • Shale
    • Quartzite
  • AAPG geologic province:
    • Great Basin province
Publication:

Morris, H.T., and Lovering, T.S., 1961, Stratigraphy of the East Tintic Mountains, Utah, with a section on Quaternary deposits by H.D. Goode: U.S. Geological Survey Professional Paper, 361, 145 p., (incl. geologic map, scale 1:96,000) [Available online from the USGS PubsWarehouse: http://pubs.er.usgs.gov/pubs/pp/pp361]


Summary:

Pg. 110-111, 112, pl. 3 (loc. 18c). Chiulos member of Great Blue formation. Lower half chiefly gray-green to greenish brown-weathering black shale; upper half chiefly massive, fine- to medium-grained, cross-bedded quartzite with a large proportion of shale and rare lenses of argillaceous, sand-streaked limestone. Thickness about 800 to 1,000 feet. Conformably underlies Poker limestone member and overlies Paymaster member (both of Great Blue formation). Age is considered Late Mississippian.

Source: Publication.


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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).