The warmth of the long summer afternoons of the most recent ice age sent great freshets of glacial meltwater, milky white with suspended rock flour, into Glacial Lake Missoula. Rock flour settled ...

This cloudiness comes from glacial flour: bits of pulverized rock ground down by glaciers that has the consistency of flour. Several meltwater streams rich with the particles, sometimes called ...

As glacial ice moves very slowly downhill ... These rocks grind together, creating tiny grains of dust, called rock flour. Some glaciers flow all the way to the sea and when they get there ...