The rocks that form the Canadian Shield were formed about two billion years ago, when they were under water in the Precambrian era. The rocks are mostly sedimentary, though there are some igneous rocks that date back 1.25 to 1.5 billion years. More recent rocks that were formed above these ancient layers were removed by the scouring action of glaciers that covered northern North America in the several ice ages in the past 100,000 years.
The last ice age scraped the rocks in a NNE (north-north-east) to SSE
(south-south-east) direction. The soil on which the grasses and other vegetation
grow in this part of the continent are the result of gradual sediment
buildup since the last ice age.
More history of Regina