Chapter 10

Front 1

Angle of Repose

Back 1

The maximum slope angle that allows rock, sand, clay, and debris to stay in place without movement; depends on slope material and moisture content.

Front 2

Carbonation

Back 2

The process whereby carbonic acid weathers rocks by slowly dissolving minerals.

Front 3

Chemical Weathering

Back 3

The decomposition or decay of minerals in rocks by chemical reactions with water, oxygen, and acids.

Front 4

Creep

Back 4

The extremely slow downhill movement of soil and regolith.

Front 5

Debris Avalanche

Back 5

Formed when an unstable slope collapses and debris are translated away from the slope.

Front 6

Denudation

Back 6

The long term sum of processes that cause the wearing away of the earth’s surface leading to a reduction in elevation and relief of landforms and landscapes. (volcanoes and earthquakes uplift and expose the continental crust to weathering, erosion and mass wasting)

Front 7

Differential Weathering

Back 7

When softer rocks weather away leaving behind harder and more resistant rock.

Front 8

Exfoliation

Back 8

(layers of rock peeling away) The process of removal of overlying rock load from bedrock by processes of denudation, accompanied by expansion and often leading to the development of sheeting structure.

Front 9

Frost Action

Back 9

In cold climates frost cracking occurs, which is when water penetrates the joints or pores in the bedrock and then weakens or breaks the rock through freezing and expansion.

Front 10

Hydration Joints

Back 10

A fraction within bedrock, usually occurring in parallel and intersecting sets of planes.

Front 11

Landslide

Back 11

A rapid sliding of large masses of bedrock on a steep mountain slope of from a high cliff.

Front 12

Mass Movement:

Back 12

Also known as mass wasting, which is the process by which soil, sand, regolith, and rock move downslope typically as a mass, largely under the force of gravity but largely affected by water and water content as in mudslides.

Front 13

Mudflows

Back 13

A flowing mixture of water and soil or regolith that flows rapidly downhill.

Front 14

Oxidation

Back 14

The chemical union of free oxygen with metallic elements in minerals, which makes minerals unstable and causing rock to degrade in strength and crumble.

Front 15

Parent Material

Back 15

The underlying material from which soil horizon forms.

Front 16

Physical Weathering

Back 16

The breakup of massive rock (bedrock) by physical forces at or near the Earth’s surface.

Front 17

Pressure-Release Jointing

Back 17

There is a reduction in pressure on a rock due to removal of overlying material. This allows rocks to split along planes of weakness, called joints.

Front 18

Regolith

Back 18

The layer or rock and mineral particles that lies above bedrock.

Front 19

Rockfall

Back 19

The most visible form of mass wasting, in which rocks fall down steep slopes or cliff slides, bringing with them soil or regolith.

Front 20

Salt Weathering

Back 20

In dry climates salt crystal growth in crevices and pores creates pressure. It can disintegrate the rock, the water is then drawn up through the openings, and then evaporates once it reaches the surface, leaving behind the tiny salt crystals which over time will break the rock apart.

Front 21

Scarification

Back 21

A general term for artificial excavations and other land disturbances produced for extracting or processing mineral resources.

Front 22

Slopes

Back 22

Patches of the land surface that are inclined from the horizontal.

Front 23

Spheroidal Weathering

Back 23

A type of chemical weathering that creates rounded boulders whenever a mass of rock experiences a drastic reduction in ambient heat and pressure.

Front 24

Talus Slope

Back 24

An accumulation of rock fragments falling from a rock face or cliff, collecting at the bottom in a cone shaped pile.

Front 25

Weathering

Back 25

All the processes that physically disintegrate or chemically decompose a rock at or near the Earth’s surface.