The property is situated on the eastern margin of the Coast Plutonic Complex, and underlain by upper Triassic King Salmon Formation sediments consisting of andesitic volcanic and volcani- clastic rocks and limestone. On the northeast part of the property Upper Triassic Sinwa Formation limestone occurs underlain by the northeast diping King Salmon thrust fault. The rocks are intruded by intermediate plutons and dykes of Jurassic or Cretaceous age, which caused partial skarnification.