Dean M. Chriss
Ice Versus Rock
(Click image to enlarge)
This enormous glacier flows down a mountainside like a river of ice.
Blocked by a large rock outcrop it flows around, making a greater than 90 degree
turn. In doing so it grinds against the obstacle with
rocks that are carried within the ice. Some of these rocks are enormous and some are
finer than sand. This very slow but steady grinding pulverizes the carried
rocks and the obstacle into progressively smaller pieces, some of which become a
fine flour like dust that is called "glacial flour. Glacial flower
particles are so fine they can be suspended in the glacier's melt water,
coloring it an iridescent green-blue.