• The process by which rock and minerals are
• The physical process of removing and
broken down into smaller pieces or altered in
transporting weathered materials (broken-down
place due to physical , chemical , or biological
pieces ) from one location to another through
agents.
the action of wind, water , ice , or gravity.
Weathering and Erosion
Two of the primary agents of change on Earth are wind and water.
Wind and water interact powerfully to constantly change Earth’s
surface through weathering and erosion.
Weathering is the process of breaking down or dissolving minerals
and rocks on Earth’s surface.
Water, ice, temperature changes, acids, salt, plants, and animals can
all be agents of weathering.
Once rock is broken down, wind, water, and gravity can transport
the bits of rocks and minerals away.
This process is called erosion.
No rock on Earth’s surface is hard enough to resist weathering.
Weathering can be a mechanical or a chemical process, and often the two
types work together.
Chemical weathering occurs when the materials that make up rocks and
soil are changed by chemical means.
Sometimes carbon dioxide from the soil or air combines with water to
produce carbonic acid.
This is a weak acid that can dissolve rock, and it is particularly effective
on limestone.
Rust, through the process of oxidation, is also an agent of chemical
weathering.
Mechanical (or physical) weathering causes rocks to crumble.
One way water weathers rocks is the freeze-thaw process.
Water enters cracks in the rock.
When the temperatures drop and the water freezes, it expands.
This places pressure on the rocks around it, causing rocks to crack and
split over time.
