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Map showing publication footprint
  • Usage in publication:
    • North Shore volcanic complex
  • Modifications:
    • First described(?)
    • Geochronologic dating
  • AAPG geologic province:
    • Lake Superior region
Publication:

Gehman, H.M., 1958, The petrology of the Beaver Bay complex (Minnesota) [abs.]: Institute on Lake Superior Geology, April 21-22, 1958, v. 19, no. 4, p. 771-772., (p. 1, Minneapolis, MN, Univ. Minnesota Center of Continuation Study [1958]; Dissert. Abs., O)


Summary:

Pg. 1. North Shore volcanic complex is intruded by gabbros of Beaver Bay complex. On basis of K/A 40 dating (Goldich and Nier, p. 11, this report), group is considered middle late Precambrian. Middle Keweenawan.

Source: US geologic names lexicon (USGS Bull. 1200, p. 2771).


Map showing publication footprint
  • Usage in publication:
    • North Shore volcanics
  • Modifications:
    • Named(?)
  • Dominant lithology:
    • Basalt
    • Rhyolite
  • AAPG geologic province:
    • Lake Superior region
Publication:

Grout, F.F., Sharp, R.P., and Schwartz, G.M., 1959, The geology of Cook County, Minnesota: Minnesota Geological Survey Bulletin, no. 39, 163 p., (incl. geologic map, scale 1:48,000(?))


Summary:

Pg. 13 (table 1), 30-40. Recognized in Lake and Cook Counties, northeastern Minnesota. Described in Cook County as North Shore volcanics of Keweenawan group. Volcanic group comprises rocks which consist predominantly of basalt and rhyolite flows with interbedded tuffs, shales, conglomerates, and breccias. Flows and associated rocks occupy about one-half of Cook County. Principal belt lies between coast of Lake Superior and upper contact of Duluth gabbro complex. Age is Precambrian.

Source: US geologic names lexicon (USGS Bull. 1200, p. 2771).


Map showing publication footprint
  • Usage in publication:
    • North Shore Volcanic Group
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Lake Superior region
Publication:

Green, J.C. (leader), 1972, Field trip guidebook for Precambrian rocks of the North Shore Volcanic Group, northeastern Minnesota: Minnesota Geological Survey Guidebook Series, no. 3, 36 p., Prepared for the GSA 85th Ann. Mtg., Minneapolis, MN, 1972


Summary:

Divided into 16 informal lava units (table 3) on northeast limb (Tofte-Grand Portage) of group and into 13 informal lava units (table 4) on southwest limb (Tofte-Nopeming) of group. Study area is northeast Minnesota, Lake Superior region. Age is Late Precambrian. Report includes generalized geologic map, chemical analyses, generalized characteristics, correlation chart.

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


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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 ( ).

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