Tectonic Unit: mPV
         Name: Purcell
 
  Description: Purcell Supergroup contains altered basaltic to
               andesitic volcanics (mPv), upper, white and grey
               crossbedded orthoquartzite, olive grey shale and
               purple and ren 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 along with: Wernecke
               Supergroup contains diatremes and breccia
               complexes.; marine
 
    Formation: Foreland Belt
                  Ancestral North America
                       mP  Purcell Volcanics
 
    Age Range: Middle Proterozoic
  Maximum Age: 1600 Ma
  Minimum Age: 1000 Ma