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National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Copper City Flow
  • Modifications:
    • Geochronologic dating
  • AAPG geologic province:
    • Lake Superior region
Publication:

Davis, D.W., and Paces, J.B., 1990, Time resolution of geologic events on the Keweenaw Peninsula and implications for development of the Midcontinent Rift System: Earth and Planetary Science Letters, v. 97, nos. 1-2, p. 54-64.


Summary:

U-Pb dates on four zircon fractions give an age of 1096.2 +/-1.8 Ma (66% probability of fit). Copper City is a basaltic unit within lower part of Portage Lake Volcanics. Study area is on Keweenawan Peninsula, MI, Lake Superior region.

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


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