Tectonic Unit: TrH
         Name: Hyd
 
  Description: basalt pillow lava, rhyolite flows, breccia and
               tuffs; interbedded limestone, siltstone and
               sandstone; basal polymictic conglomerate and
               coarse breccia.  Rhyolite east of Dixon Entrance
               yields a concordant U-Pb age of 188 Ma (TrJH)
 
    Formation: Insular Belt
                  Alexander Terrane
                       uTr  Hyd, Hound I., Cornwallis, Hamilton I., Burnt I.,
                            Keku, Chapin Pk., Nehenta, Puppets
 
    Age Range: Upper Triassic
  Maximum Age: 235.0 Ma
  Minimum Age: 208.0 Ma