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Map showing publication footprint
  • Usage in publication:
    • McClure Mountain Complex*
  • Modifications:
    • Named
  • Dominant lithology:
    • Syenite
  • AAPG geologic province:
    • Denver basin
Publication:

Shawe, D.R., and Parker, R.L., 1967, Mafic-ultramafic layered intrusion at Iron Mountain, Fremont County, Colorado, IN Contributions to general geology, 1967: U.S. Geological Survey Bulletin, 1251-A, p. A1-A29.


Summary:

Named for McClure Mountain, Fremont Co, CO in the Denver basin. Type area is in Ts19 and 20S, Rs72 and 73W. Includes layered rock of mafic complex, discordant rocks of mafic complex, biotite-hornblende syenite, mafic nepheline-bearing rocks, and nepheline syenite. Shows graded bedding, cross-bedding, and scour-and fill structures. Forms a small funnel-shaped intrusive complex that includes rocks at Iron Mountain and at McClure Mountain southwest of Canon City; covers about a 20 sq mi area. Assigned a Precambrian or Cambrian age.

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


Map showing publication footprint
  • Usage in publication:
    • McClure Mountain Complex*
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Denver basin
Publication:

Parker, R.L., and Sharp, W.N., 1970, Mafic-ultramafic igneous rocks and associated carbonatites of the Gem Park Complex, Custer and Fremont Counties, Colorado: U.S. Geological Survey Professional Paper, 649, 24 p. [Available online from the USGS PubsWarehouse: http://pubs.er.usgs.gov/pubs/pp/pp649]


Summary:

Age changed in Denver basin from Precambrian and Cambrian to Middle Cambrian. K-Ar ages for syenites of 508 (+/-l5) to 532 (+/-27) m.y.

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


Map showing publication footprint
  • Usage in publication:
    • McClure Mountain Complex*
  • Modifications:
    • Geochronologic dating
  • AAPG geologic province:
    • Denver basin
Publication:

Olson, J.C., Marvin, R.L., Parker, R.L., and Mehnert, H.H., 1977, Age and tectonic setting of Lower Paleozoic alkalic and mafic rocks, carbonatites, and thorium veins in south-central Colorado: U.S. Geological Survey Journal of Research, v. 5, no. 6, p. 673-687.


Summary:

Covers an area of about 46 sq km, Fremont Co, CO in the Denver basin. Includes older, largely stratiform mafic and ultramafic rocks, and younger syenitic rocks. Has averaged hornblende K-Ar age of 520 m.y.; 521 m.y. Rb-Sr; 508 m.y. averaged biotite K-Ar age, and 506 m.y. sphene F-T age. Assigned to the Middle Cambrian.

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


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

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