Tectonic Unit: mPD
         Name: Dismal Lakes
 
  Description: Wernecke Supergroup contains diatremes and breccia
               complexes.  Purcell Supergroup contains altered
               basaltic to andesitic volcanics (mPv), upper,
               white and grey crossbedded orthoquartzite, olive
               grey shale and purple and red mudstone, minor
               siltstone and conglomerate; lower, brick red and
               purple sandy and silty mudstone, red, purple and
               green siltstone and sandstone with interbeds of
               stromatolitic dolomite; marine
 
    Formation: Foreland Belt
                  Ancestral North America
                       mP   Dismal Lakes
 
    Age Range: Middle Proterozoic
  Maximum Age: 1600 Ma
  Minimum Age: 1000 Ma