Geography Chapter 10

Front 1

Landmass Denudation
Geomorphology

Back 1

Geomorphology:
the science of landforms, study their origin, evolution, form, and spatial distribution

Front 2

Landmass Denudation
Denudation

Back 2

Denudation:
any process that wears away or rearranges landforms; carried out by water, air, waves, or ice:

Hint 2

-weathering
-mass movements
-erosion
-transportation
-deposition

Front 3

Landmass Denudation
Dynamic Equilibrium Model

Back 3

Dynamic Equilibrium Model:
-ongoing adaptations to the ever changing conditions of rock structure, climate, local relief and elevation
-a balancing act between uplift and reduction, resistance and weathering.

Hint 3

Destabilizing events change the equilibrium of a system:
-heavy rainfall
-wildfire
-faulting

Front 4

Landmass Denudation
Geomorphic Threshold

Back 4

Geomorphic Threshold:
the point at which there is enough energy to overcome the resistance against movement

Hint 4

Parttern over time:
1. equilibrium stability
2. destabilizing event
3. period of adjustment
4. development of new and differernt equilibrium stability

Front 5

Landmass Denudation
Slope

Back 5

Slope:
curved, inclined surfaces that bound landforms

Front 6

Weathering Processes
Weathering

Back 6

Weathering:
the processes by which surface or subsurface rock disintegrates into mineral particles or dissolves in water;
generation of loose material overlying bedrock (regolith)

Hint 6

Regolith:
Partially weathered rock overlying bedrock, whether residual or transported.

Front 7

Weathering Processes
Bedrock

Back 7

Bedrock:
the parent rock from which weathered regolith and soils develop

Front 8

Weathering Processes
Sediment

Back 8

Sediment:
fine-grained material created from the regolith, combines with other material to form soil

Front 9

Weathering Processes
5 Characteristics of rock weathering

Back 9

1. Character of the bedrock
2. climate
3. position of the water table
4. orientation of the slope
5. vegetation

Front 10

Weathering Processes
Differential Weathering

Back 10

Differential Weathering:
uneven breakdown of rock material

Hint 10

some layers are more resistant than others

Front 11

Physical Weathering
Physical Weathering (mechanical)

Back 11

Physical Weathering (mechanical):
when rock is broken and disintegrated without chemical alteration

Front 12

Physical Weathering
Joints

Back 12

Joints:
fractures or separations in rock

Front 13

Physical Weathering
1. Root Action

Back 13

1. Root Action:
plant roots can enter crevices and break apart rocks

Front 14

Physical Weathering
2. Frost Action (freeze-thaw)

Back 14

2. Frost Action (Freeze-Thaw):
when water seeps into openings in rocks and eventually breaks open the rock by repeated freezing

Hint 14

-ice has a greater volume than water
-frost-wedging

Front 15

Physical Weathering
3. Crystallization

Back 15

3. Crystallization:
the breakdown of rocks through the precipitating out of minerals from evaporating water in rocks

Hint 15

-salt-crystal growth
-this happens a lot in arid environments

Front 16

Physical Weathering
4. Physical Weathering

Back 16

4. Physical Weathering:
when weight is removed from granite due to erosion, the pressure is reduced and the rock expands
-huge slabs can slip off (sheeting)

Hint 16

Sheeting:
a form of weathering associated with fracturing or fragmentation of rock by pressure release

Front 17

Chemical Weathering
Chemical Weathering

Back 17

Chemical Weathering:
the decomposition and decay of the minerals in rock due to chemical alteration of those minerals, always in the presence of water.

Hint 17

-no rocks are completely unresponsive to chemical weathering
-it increases as temperature and precipitation increase
-material then susceptible to erosion and mass movement

Front 18

Chemical Weathering
Spheroidal Weathering

Back 18

Spheroidal Weathering:
occurs when water penetrates joints and fractures in rock and dissolves the rock's cementing materials.

Hint 18

-sharp edges become rounded
-can work in combination with other forms of weathering

Front 19

Chemical Weathering
1. Hydration

Back 19

1. Hydration:
"combination with water"
water is absorbed by a mineral, it swells and mechanically forces grains apart.

Hint 19

-leads to granular disintegration

Front 20

Chemical Weathering
2. Hydrolysis

Back 20

2. Hydrolysis:
when minerals in rocks chemically react with water (breaks down silica), chemical reactions produce different compounds

Front 21

Chemical Weathering
3. Oxidation

Back 21

3. Oxidation:
when oxygen dissolved in water combines with certian metallic elements to form oxides.

Hint 21

-results in "rusting" of iron in rocks, reddish-brown color is iron oxide

Front 22

Chemical Weathering
4. Dissolution (acid action)

Back 22

4. Dissoultion (acid action):
simplest form of chemcial weathering
-when minerals dissolve into a solution (often water)
-aided by an acid

Front 23

Chemical Weathering
Carbonation

Back 23

Carbonation:
when carbon combines and transforms minerals containing calcium, magnesium, potassium, and sodium into carbonates.

Front 24

Karst Landscapes
Karst Topography

Back 24

Karst Topography:
areas of limestone bedrock that are easily chemically weathered;
-pitted and bumpy surface topography, poor surface drainage, and well-developed channels underground.

Hint 24

15% of earth

Front 25

Karst Landscapes
Formation

Back 25

Formation/Conditions:
-limestone must contain 80% calcium carbonate
-must have joints for water to form routes through it
-there must be an aerated zone between the ground surface and water table
-vegetation cover to supply organic acids

Front 26

Chemical Weathering
Sinkhole

Back 26

Sinkhole:
-circular depression
-created by the weathering of karst landscapes
-may collapse through the roof of an underground space

Front 27

Mass-Movement Processes
Mass-Movement

Back 27

Mass-Movement:
all downward movement of material propelled and controlled by gravity

Hint 27

-range from dry to wet, fast to slow, and large to small
-action works to waste slopes and provide raw material for erosion, transportation, and deprosition
-gravity pulls on a mass until the critical shear-failure point is reached

Front 28

Mass-Movement Processes
1. Falls and Avalances:

Back 28

1. Falls and Avalances:
Rockfall and debris avalanch, very rapid
-dry, no water

Hint 28

Rockfall:
rock falls through air

Debris Avalanch:
mass falling of rock, debris, soil

Front 29

Mass-Movement Processes
2. Landslides

Back 29

2. Landslides:
cohesive rapid movement of mass that is not saturated
-slower
-involves water

Front 30

Mass-Movement Processes
3. Flows

Back 30

3. Flows:
-high pressure content
-mudflows, debris flow, occur in stream valleys

Hint 30

-pyroclastic flow (gas)
volcanoes

Front 31

Mass-Movement Processes
4. Creep

Back 31

4. Creep:
Soil Creep:
persistant movemtn of surface soil
-slow