| Description |
A study of the brecciation in the Ontario Mine, East Flank Ore Bodies indicates a variety of structural types of brecciation are present. These are; (1) tectonic breccias, (2) bedded or stratiform breccias, (3) breccia pipes, (4) pebble dikes, and (5) igneous contact breccias. Multiple ages of brecciation were recognized in the Ontario Mine. Pre-mineral breccias are distinguished by the replacement of both the fragments and matrix with sulfides and replacement with silica associated with the ore fluids. Post-mineral brecciation includes tectonic breccias and collapse structures. Three types of brecciation are distinguished on the basis of origin. These are; (1) injection breccias, (2) collapse breccias, and (3) tectonic breccias. A significant amount of mineralization is localized by breccition. However, not all of the breccias are mineralized. Pre-mineral brecciation along the 1809 Ore Horizon and the North Ore Zone has provided open structures which form the host rocks for these ore bodies. It is believed that some of the pre-mineral breccias will be useful as exploration guides in the Ontario Mine. |
