Category of Process How it works Case specific examples of where it occurs and why
sub-aerial
process
Weathering Physical/mechanical - Freeze-thaw weathering : disintegration of Snowdonia
rocks into smaller rocks. It occurs when rocks The rocks on the rugged ridge have been broken down
are porous or permeable, and daytime into jagged fragments by freeze thaw weathering.
temperature is different to night time This occurred in Snowdonia as the temperature often
temperature. drops below freezing at night at this area.
- Water enters the crack in the rock at day The cooled month is February where the average
- At night, when temp drops, the water freezes coldest temperature is -2 degrees Celsius and the
and expands, which increases the pressure on average highest is 3 degrees. The warmest months is
the rock, widening the crack July-August where the average lowest temperature is 8
- The ice melts as temperature rise again at day degrees and the highest is 14 degrees.
time
- This process repeats itself until the rock
breaks apart
- The material is loose to fall on the shore
Periglacial Head, Perranmoth, Cornwall
- Freeze-thaw weathering leads to the bedrock
being broken down into smaller angular
fragments
, Exfoliation: it’s a process in which curved plates of
rocks are stripped from rock below. It occurs when the Exfoliation domes best develops with igneous rock,
daytime and night-time temperatures are especially granite rocks, as pressure is built and
distinctively different on dry rock released when the rock is moved to the surface by
1. The rock mass at depth is under high tectonic process. Example of this can be seen at
pressure from underlying rocks Yosemite national park in USA, where exfoliation
2. During the day rock surface heats up and gradually created the more rounded appearance of the
expands dome after erosion of overlying rock and the removal of
3. Rock surface cools down and contracts at confining pressure on the pluton-solidified magma
night time chamber.
4. The joints form in the outer part of the
rock
5. The process of expansion and contraction
of the surface layers repeats, resulting in
the gradual disintegration of the top
layers
6. Exfoliation may occur parallel to the rock’s
outer surface when water enters the
crack, resulting in chemical break down of
minerals
sub-aerial
process
Weathering Physical/mechanical - Freeze-thaw weathering : disintegration of Snowdonia
rocks into smaller rocks. It occurs when rocks The rocks on the rugged ridge have been broken down
are porous or permeable, and daytime into jagged fragments by freeze thaw weathering.
temperature is different to night time This occurred in Snowdonia as the temperature often
temperature. drops below freezing at night at this area.
- Water enters the crack in the rock at day The cooled month is February where the average
- At night, when temp drops, the water freezes coldest temperature is -2 degrees Celsius and the
and expands, which increases the pressure on average highest is 3 degrees. The warmest months is
the rock, widening the crack July-August where the average lowest temperature is 8
- The ice melts as temperature rise again at day degrees and the highest is 14 degrees.
time
- This process repeats itself until the rock
breaks apart
- The material is loose to fall on the shore
Periglacial Head, Perranmoth, Cornwall
- Freeze-thaw weathering leads to the bedrock
being broken down into smaller angular
fragments
, Exfoliation: it’s a process in which curved plates of
rocks are stripped from rock below. It occurs when the Exfoliation domes best develops with igneous rock,
daytime and night-time temperatures are especially granite rocks, as pressure is built and
distinctively different on dry rock released when the rock is moved to the surface by
1. The rock mass at depth is under high tectonic process. Example of this can be seen at
pressure from underlying rocks Yosemite national park in USA, where exfoliation
2. During the day rock surface heats up and gradually created the more rounded appearance of the
expands dome after erosion of overlying rock and the removal of
3. Rock surface cools down and contracts at confining pressure on the pluton-solidified magma
night time chamber.
4. The joints form in the outer part of the
rock
5. The process of expansion and contraction
of the surface layers repeats, resulting in
the gradual disintegration of the top
layers
6. Exfoliation may occur parallel to the rock’s
outer surface when water enters the
crack, resulting in chemical break down of
minerals
