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Geologic Unit: Junction
Map showing publication footprint
  • Usage in publication:
    • Junction Formation
  • Modifications:
    • Named
  • Dominant lithology:
    • Schist
    • Gneiss
    • Quartzite
  • AAPG geologic province:
    • Southern Rocky Mountain region
Publication:

Lickus, R.J., and LeRoy, L.W., 1968, Precambrian structure and stratigraphy along the mountain front west of Golden, Jefferson County, Colorado; a reconnaissance study: Colorado School of Mines Quarterly, v. 63, no. 1, p. 129-165.


Summary:

Named for junction of Golden Gate Canyon road and Crawford Gulch road. Type area designated along mountain front and in SW1/4 SE1/4 sec 17, T3S, R70W, Golden quad, Jefferson Co, CO in the Southern Rocky Mountain region. Formerly called interlayered amphibolite and biotite-plagioclase-quartz gneiss. Consists of muscovite-sillimanite, gneissic schist to schistic gneiss containing numerous thin quartz and granitic stringers and pods. In west part of area consists of an 8-10 ft fine- to medium-grained, thin-bedded quartzite named Green Ranch Quartzite Member which usually occurs in middle or top part of formation. Junction ranges from 0 (on northwest flank of Baughman nose) to 900 ft. Overlies Cressman's Gulch Formation (new). Underlies Golden Gate Canyon Formation (new). Geologic map. Cross section. Precambrian age.

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


Map showing publication footprint
  • Usage in publication:
    • Junction Formation
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Southern Rocky Mountain region
Publication:

Tweto, Ogden, 1977, Nomenclature of Precambrian rocks in Colorado, IN Contributions to stratigraphy: U.S. Geological Survey Bulletin, 1422-D, p. D1-D22.


Summary:

Is one of several units defined in a narrow belt along east-central Front Range, near Golden, Jefferson Co, CO in the Southern Rocky Mountain region. Of doubtful use elsewhere. Assumed direction of stratigraphic sequence is debatable. Belongs with pre-1,700 m.y. metamorphic complex, or of Precambrian X 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 ([ ]).

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