Colorado Paper - Occurrence of Copper Glance, North of Lake Huron, With Notes on the Structure of the Locality

The variety of copper-ore to which these notes refer is cornparatively rare, and, so far as I am aware, has not been recorded hitherto as occurring in Ontario. Moreover, the rocks of this locality differ so much in nature and mode of occurrence from the orebearing rocks of the western United States, that a description of them may be interesting. A line drawn upon a map of the region of the great lakes from the mouth of the Severn river at the Southern end of Georgian Bay, following the Canadian shore northwestward, and leaving Manitoulin island to the south, will describe the boundary between the Archaean rocks lying north of it and the Silurian rocks southward.