Chapter 12

Question 1

Weathering

Answer 1

Processes that change the physical and chemical character of rock at or near the surface.

Breaks down rocks that are either stationary or moving.

Tightly bound crystals loosened and altered when exposed to air and water during weathering.

Question 2

Erosion

Answer 2

The picking up or physical removal of rock particles by an agent such as running water, or glaciers.

Weathering helps break down solid rock into particles that are easily eroded(carried) away by rainwater..

Question 3

Transportation

Answer 3

Movement of eroded particles by agents such as rivers, waves, wind, and glaciers. Weathering processes continue during transportation.

Question 4

Mechanical Weathering

Answer 4

Physical disintegration
Includes several processes that break rock into smaller pieces.
Little to no chemical change in the rock, only physical.

Ex: water freezing in cracks and expanding breaking rock.

Question 5

Chemical Weathering

Answer 5

Decomposition of rock from exposure to water and atmospheric gases.
As rock is decomposed, new chemical compounds form.

Question 6

Spheroidal Weathering

Answer 6

Occurs where rock has been rounded by weathering from an initial blocky shape.

It is rounded because chemical weather happens more rapidly in the corners and edges than the smooth faces of the rock.

Question 7

Differential Weathering

Answer 7

Describes the tendency for different types of rock weather at different rates.

Ex: shale(soft) weathers faster than sandstone(hard).

Question 8

Pressure Release

Answer 8

Type of mechanical weathering where the reduction of pressure on a body of rock can cause it to crack as it expands.

Sheet joints develop parallel to the outer surface of the rock as the outer part expands more than the inner part.

Exfoliation: on slopes, gravity may cause the rock between joints to break loose in slabs from the granite mass, spalling of rock layers.