Considerable prospecting had been done in the Porcupine Creek area prior to 1910. About 4.8 kilometres up the valley, small fractures in slate and calcareous slate of the Middle Cambrian Chancellor Group contain vein material, 2 to 15 centimetres wide, consisting of pyrite and argentiferous galena in a gangue of fluorite, ankerite, muscovite and lepidomelane.