Ch. 5, p.
124: #4-6, 12, 13
4. Why do
stone buildings tend to weather more rapidly in cities than in rural
- Air pollution in urban areas
makes water more acidic and more effective at dissolving rock
material. Pollution of that sort is not as common in rural
at least three processes that mechanically weather rock.
- In frost wedging, the
expansion of ice that freezes in cracks causes the cracks to widen with
each generation of freezing. In pressure release, rocks that form
at depth under great pressure may expand when overlying rock material
is eroded away. Biological activity, including root growth of
plants and animal burrowing may loosen and break up rocks.
6. How can
mechanical weather speed up chemical weathering?
- Mechanical weathering
increases the overall surface area when it breaks down the rock into
smaller fragnments. Increased surface area provides more surface
for chemical weathering to attack the rock, allowing chemical
weathering to speed up.
disintegration of rock into smaller pieces is called:
- d. mechanical weathering
decomposition of rock from exposure to water and atmospheric gases is
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