Rock flour, or glacial flour, consists of fine-grained, silt-
sized particles of rock, generated by mechanical grinding of
bedrock by glacial erosion or by artificial grinding to a
similar size. Because the material is very small, it becomes
suspended in river water making the water appear cloudy, which
is sometimes known as glacial milk. When the sediments enter a
river, it turns the river's color gray, light brown, iridescent
blue-green, or milky white. If the river flows into a glacial
lake, the lake may appear turquoise in color as a result. When
flows of the flour are extensive, a distinct layer of a
different color flows into the lake and begins to dissipate and
settle as the flow extends from the increase in water flow from
the glacier during snow melts and heavy rain periods. Examples
of this phenomenon may be seen at Lake Louise and Peyto Lake in
Canada and Gjende lake in Norway. Typically, natural rock flour
is formed during glacial migration, where the glacier grinds
against the sides and bottom of