The Castleguard karst, Main Ranges, Canadian Rocky Mountains

The Castleguard karst is partly overlain by the Columbia Icefield. Subglacial water is drained through the karst to constricted springs in the Castleguard Valley. The apparent immaturity of the springs is contradicted by their rapid response and recession, and by rapid groundwater velocities. The inferred age of 700,000 yr. is also sufficient for conduit development. It is concluded that recent glaciation has blocked a pre-existing conduit, throwing the aquifer into temporary disorder.