Geoscience for central Vancouver Island communities
Different rocks, different landscapes
Rocks dictate our landscape and the location of resources, water, and people. Hard granitic and metamorphosed volcanic and sedimentary rocks form the central, mountainous spine of Vancouver Island, whereas sedimentary rocks underlie the more habitable coastal lowlands. Belts of limestone contain caves. The mountains of central Vancouver Island strongly affect the region's climate by producing a rain shadow to the east and torrential rains in the coastal rainforest to the west.
Under Nanaimo: A Record of Ancient History
The rocks beneath our feet record nearly 400 million years of Earth history. The oldest rocks, referred to as 'Wrangellia' by geologists, include limestone and volcanic rocks that formed below a deep ocean. These rocks are cut by granite that was injected in a molten state and later cooled and solidified. During the 'age of dinosaurs', the rocks of Wrangellia were buried by sediments that transformed into sedimentary rocks of the 'Nanaimo Group', now the foundation of Nanaimo. Finally, a partial blanket of glacial till, sand, and gravel was left behind by glaciers during the ice age.