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Mechanical
Weathering
Weathering
is the process that breaks rocks down into smaller pieces, eventually creating
soil. Mechanical weathering is when water flows into small cracks in rocks
during winter, and then freezes, splitting the rock apart (water
expands when frozen).
More water would flow in around that, and split the rock open even more. An
example of this is swinging and ax upon firewood, splitting it into kindling.
However, ice isn't the only way to "mechanically" weather rocks:
in deserts, the wind blows sand ageist rocks and scours away like a scrub
brush, while a rock in stream is smoothed, while the excess becomes sand or
silt. This proces is very similar to erolion, but is different due to the moving (erosion) and removing (weathering). As seen in the previous photo, the rock is scarred and warped around the
base, and straight flaws curve inward to traverse vertically along to the
top. The wind-blown debris and rainfall has rounded the top, and at the bottom,
these cracks have widened and released pebbles to the ground. Below are an
image of a rock split by frozen water, and another image of a rock rounded by wind and
water. Can you tell the difference?
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