rock flour

Canada's lakes are becoming less blue — but that could be good for fish

Canada's lakes are becoming less blue — but that could be good for fish

If you drive the Icefields Parkway through the Canadian Rockies, you'll pass multiple turquoise-coloured lakes that are popular with tourists for taking photos. The lakes get their iconic colour from rock flour, which is similar in appearance to baker's flour used for making bread. Rock flour is made from glaciers grinding rocks into powder, which can take thousands of years.