Tectonic Unit: Ov
         Name: Rocky Mountains
 
  Description: amygdaloidal basalt of Ordovician age;
               associated with Rocky Mountains Assemblage (CDR).
 
    Formation: Omineca Belt
                  Ancestral North America
               Foreland Belt
                  Ancestral North America
 
    Age Range: Ordovician
  Maximum Age: 510.0 Ma
  Minimum Age: 439.0 Ma