Geology of British Columbia

The geology of British Columbia is a function of its location on the leading edge of the North American continent. The mountainous physiography and the diversity of rock types and ages hint at the complex geology, which is still undergoing revision despite a century of exploration and mapping.
The country's most prominent geological features are mountain ranges, including the North American Cordillera, which stretches from Southern Mexico to Alaska.
Terrane theory.
Terrane theory was first proposed by Jim Monger of the Geological Survey of Canada and Charlie Rouse in 1971 as an explanation for a set of fusilinid fossils found in central British Columbia. Rather than use facies changes or seaways (which were common explanations at the time), the two geologists proposed that the fossils in question had been part of an assemblage of rocks that had migrated across the Pacific Ocean to their present location. This theory was then developed by Porter Irwin and Davy Jones of the US Geological Survey to its common definition of "fault bounded regional geologic entities, each characterized by a different geologic history than its neighbours"